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• A core-shell magnetic MOF was proposed for the extraction of pesticides. • The mechanism of analyte adsorption is mediated by the adsorbent shell layer. • Nine pesticides were extracted from different herbal infusions using adsorbent. • The sample preparation method was fast due to the use of magnetic adsorbent. • High extraction recoveries and enrichment factors and low detection limits were obtained. This paper introduces an innovative technique for extracting pesticides from herbal infusions using a core-shell magnetic adsorbent (i.e., Cu-BTC@Fe 3 O 4) where achieving a notable enrichment factor for the target pesticides by coupling with a dispersive liquid-liquid microextraction method. To validate the successful synthesis of the adsorbent, a range of analytical techniques were utilized including vibrating sample magnetometer, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray, and Brunauer-Emmett-Teller analyses. A vortex agitation and an external magnetic field were used during the extraction process to aid the analytes' desorption and adsorbent separation, respectively. Also, a mixture of iso -propanol and deionized water was used to desorb the analytes from the adsorbent surface. The resulting supernatant containing the desorbed pesticides was mixed with 1,2-dibromoethane as the extraction solvent and then injected into an aqueous medium. After centrifugation, 1 μL of the sedimented phase was introduced into the gas chromatograph system equipped with a flame ionization detector. The reliability of the proposed methodology was confirmed by obtaining low relative standard deviations (1.0–8.5 %), acceptable extraction recoveries (39–93 %), substantial enrichment factors (195–475), calibration curve linearity (r2=0.993–0.998), and significantly low limits of quantification (0.34–3.0 μg L −1) and detection (1.1–9.9 μg L −1). Absence of matrix effects with relative recovery values of 80–120 % for real samples, minimal use of the adsorbent and extraction solvent, a reduction in extraction time due to the elimination of two centrifugation steps (facilitated by an external magnetic field), and the use of environmentally friendly solvents collectively highlight the advantages and significant values of this approach. [ABSTRACT FROM AUTHOR]

• Extraction of PCBs from water samples using CO 2 -responsive extractants. • Combining SDES with HLLME allows for easy phase separation by passing CO 2. • Using homemade CO 2 is more economical and portable than using cylinder gas. • This method is characterized by being sensitive, green and fast. A homogeneous liquid-liquid microextraction technique based on switchable deep eutectic solvent (SDES-HLLME), combined with gas chromatography-triple quadrupole tandem mass spectrometry (GC–MS/MS), was developed for the extraction and analysis of 16 polychlorinated biphenyls (PCBs) in water samples. CO 2 -responsive switchable deep eutectic solvent (SDES), which consists of monoethanolamine (MEA) being used as a hydrogen bond acceptor (HBA) and 3-methoxyphenol (3-MP) being used as a hydrogen bond donor (HBD), was used as the extractant, thus providing an environmentally friendly alternative to conventional toxic organic solvents. The study systematically investigated the effects of various parameters on extraction efficiency, including the type and volume of SDES, vortexing duration, CO 2 bubbling time, centrifugation rate and time, ionic strength. Optimal extraction conditions were identified as follows: 40.0 μL of SDES, vortexing for 40.0 s, CO 2 bubbling for 2.0 min, 5.0 % (w/v) salt concentration, a centrifugation rate of 5000 rpm, and a centrifugation duration of 3.0 min. Under these optimal conditions, the method exhibited a linear range of 0.1–300 ng·mL−1, with limits of detection (LODs) and quantification (LOQs) ranging from 0.003 to 0.096 ng·mL−1 and 0.009 to 0.321 ng·mL−1, while the relative standard deviation (RSD) <7.98 %. Finally, this method was successfully applied to determine the concentrations of 16 PCBs in various environmental water samples, yielding satisfactory recovery rates. This method provides a green, convenient and accurate new idea in the field of HLLME research. [ABSTRACT FROM AUTHOR]

The Small Volume Ethyl Acetate based Liquid-Liquid Extraction (SVEA-LLE) method, using Atmospheric Pressure Gas Chromatography-Mass Spectrometry (APGC-MS/MS) with Dual Head Robotic Tool Change (DH-RTC) Prep and Load (PAL) autosampler, was evaluated for the analysis of 17 PAHs in water and wastewater. The extraction method was first evaluated for extraction efficiency with respect to time using a one-way Analysis of Variance (ANOVA) and the effect of acidification. Method validation was performed as per SANTE/11312/2021 v2 2024 for analysis of PAHs in wastewater. Linearity was determined over a range of 5 to 80 ng/ml, meeting the acceptable coefficient of determination (r2) and the values of % deviation from back-calculated concentration. The method was observed to be sensitive enough, as the estimated Limits of Detection (LOD) and Quantification (LOQ) were observed to be lower than or close to the Limits specified in EPA 625.1/2016 method, without the need for evaporative concentration. During the method validation trials, it was observed that 82.71 % of the observations were below 10 % RSD, 14.19 % were in the range of 10 % to 15 % RSD, and 3.08 % were between 15 % and 20 % RSD (n = 6). Similarly, in the case of mean % recovery, 92.59 % of the observations were between 80 to 120 % recovery, 3.70 % of the observations were between 70 to 80 % recovery, 3.08 % of the observations were 120 to 130 % recovery (n = 6). It was observed that mean % recovery of robustness study (n = 18) ranged from 90.21 to 117.82 (observed for phenanthrene and benzo (a) pyrene respectively). Further, the % RSD from robustness study ranged between 5.11 to 18.98 (observed for acenaphthylene and pyrene respectively). Measurement Uncertainty of all the analytes ranged from 3.73 to 8.92 % (observed for fluorene and pyrene, respectively). The method described has been observed to be fit for purpose, as it meets the method validation requirements with acceptable results in PT participation. The greenness assessment of the method using tools like the Analytical Eco-Scale (AES) and the Green Analytical Procedure Index (GAPI) indicated that method ranks excellent in greenness evaluation and is eco-friendly. The optimized sample preparation method is short, safe, and easy with an extract suitable for direct injection onto GC column, eliminating the concentration and reconstitution steps for high-throughput analysis of PAHs in water and wastewater. • Eco-friendly method meets sensitivity requirement without evaporative concentration. • Enhanced selectivity due to use of PAHs specific column and soft ionization source. • Method accuracy proved with validation, MU calculation and PT participation. • Simple alternative to complex conventional methods for PAHs testing in water. • High-throughput method ranked excellent in greenness evaluation by AES and GAPI. [ABSTRACT FROM AUTHOR]

• A novel method was developed for the detection of vitamins D2, D3, K1, and K2. • The method was applied in yogurt fortified with nanoencapsulated vitamins D and k. • The QuEChERS-UPLC-APCI-MS/MS approach shows an excellent linearity and sensitivity. • The optimized method demonstrates excellent precision, accuracy, and recovery rates. • This approach outperforms traditional and alternative extraction techniques. A novel approach was developed to simultaneously determine the contents of vitamins D 2 , D 3 , K 1 , and K 2 in yogurt fortified with nanoencapsulated vitamins D and K. This method combines QuEChERS extraction with UPLC-APCI-MS/MS analysis. Optimization of the QuEChERS process included fine-tuning the addition of salts using response surface methodology based on the Box–Behnken design. Under the optimized conditions, the developed method exhibited an excellent linearity (R2 > 0.999) across concentrations ranging from 0.5 to 500 µg/L. The limits of detection and quantification (LOD and LOQ) were found to be 0.01–0.04 µg/L and 0.04–0.11 µg/L, respectively, with precision, accuracy, and recovery rates exceeding 94.88 %, and accompanied by acceptable relative standard deviations. Comparative analysis with traditional methodologies revealed the significant advantages of the proposed approach. Previous techniques such as liquid–liquid extraction combined with saponification are time-consuming and require high sample quantities. In addition, dispersive liquid–liquid microextraction requires a long analysis time and exhibits a poor sensitivity, particularly in terms of its LOD and LOQ values. In contrast, our method offers a straightforward, efficient, and reliable sample preparation technique suitable for detecting vitamins D 2 , D 3 , K 1 , and K 2 in a yogurt matrix. This study not only demonstrates the feasibility of applying the QuEChERS method for stable vitamin quantification in yogurt, but it also represents an innovative contribution to enhancing the detection sensitivity and efficiency in food analysis. By emphasizing these methodological advancements and comparative benefits, this research underscores the significance of adopting advanced analytical approaches in food science. [ABSTRACT FROM AUTHOR]

• A novel large-pore covalent organic framework (TABPT-SPDA-COF) is presented. • TABPT-SPDA-COF has high size selectivity for polypeptide antibiotics (PPTs). • TABPT-SPDA-COF is qualified for the solid phase extraction of PPTs in foods. • TABPT-SPDA-COF-SPE-UHPLC-MS exhibits low LODs and excellent reproducibility. The precise determination of polypeptide antibiotics (PPTs) in foods has been always challenging because of the interference of various endogenous peptides in complex matrix. Herin, a novel large-pore covalent organic framework (TABPT-SPDA-COF) with accessible pore size of 7.9 nm was synthesized as a solid phase extraction (SPE) absorbent for efficiently enriching four PPTs existed in foods originating from animals. The parameters of SPE process were systematically optimized. Subsequently, four PPTs were determined by UHPLC-MS/MS. Under the optimal conditions, TABPT-SPDA-COF shows outstanding enrichment capacity for PPTs in contrast to commercial absorbents ascribed to size selectivity and multiple interaction effects. The method exhibits excellent linear range (0.005–100 ng mL−1), satisfactory limits of detection (0.1 pg mL–1) as well as relative recoveries (86.2–116 %). This work offers a practicable platform to monitor trace PPTs from complex animal-derived foodstuffs. [ABSTRACT FROM AUTHOR]

• Single set of descriptors can be used with both Abraham's and Goss-Modified model. • When electron lone pair interactions are important the Goss model provides a poor fit. • Solvents containing perfluoroalkyl groups exhibit a poorer fit to the Goss model. • Abraham's model exhibits a higher statistical fit quality in general. The solvation parameter model uses six descriptors identified as excess molar refraction, E, dipolarity/polarizability, S, overall hydrogen-bond acidity, A, overall hydrogen-bond basicity, B, McGowan's characteristic volume, V, and the gas-liquid partition constant on hexadecane at 25 °C, L to model the distribution of neutral compounds in biphasic systems. Abraham's version of this model uses all six descriptors with two separate linear free energy relationship models for the transfer of compounds from a gas phase to a condensed phase and between condensed phases. Goss proposed a modification to this model that uses a single calibration model regardless of the physical state for each phase and five of the descriptors employed in Abraham's model (E descriptor is eliminated). The capability of Abraham's model and the Goss-modified model to characterize the contribution of intermolecular interaction to retention for gas and reversed-phase liquid chromatographic systems and distribution in liquid-liquid partition systems is evaluated using the WSU compound descriptor database. These more accurate values for the Abraham descriptors have not been utilized previously for the evaluation of the Goss-modified model and should be more capable of discerning subtle differences in model performance. It is shown that model quality defined by statistical parameters favors Abraham's model over the Goss-modified model with differences in model quality greater for systems in which Abraham's model indicates a significant contribution from electron lone pair interactions and for systems in which one phase is a solvent containing perfluoroalkyl substituents. There is a small systematic difference for the terms describing the combined contributions of cavity formation and dispersion interactions and for interactions of a dipole-type. The contribution of hydrogen-bonding interactions is virtually identical for the two models. The model intercepts are generally different and potentially assigned to a larger contribution from lack-of-fit for the Goss-modified model. Although the Abraham model descriptors have been routinely employed for applications using the Goss-modified model the possibility that Goss-model specific descriptors should be employed was evaluated. Using the Solver method and Goss-model specific calibration models for chromatographic and liquid-liquid partition systems a new set of Goss-specific descriptors was calculated for 28 varied compounds. These descriptors show good statistical agreement with the Abraham descriptor values with an average deviation of 0.009, -0.003, -0.004, and -0.023, respectively, for the S, A, B, and L descriptors, corresponding to a relative absolute deviation in percent of 2.2 %, 3.9 %, 4.3 %, and 1.2 %, respectively. [ABSTRACT FROM AUTHOR]

• A method for the analysis of organic pollutants in oral bioavailable fraction was developed. • Successfully validation results were obtained and applied to PM 10 samples. • PAHs family were quantifiable in the oral bioavailable fraction. • TCPP is the only OPFR found in bioavailable fractions of samples. In recent years, scientists have started evaluating the portion of PM-bound pollutants that may be liberated (bioaccessible fraction) in human fluids and spread through the digestive system ultimately entering systemic circulation (known as the bioavailable fraction). In the current research, an analytical procedure was validated and applied to characterize the oral bioavailable fraction of PM 10 samples. The approach encompassed the determination of 49 organic contaminants. The proposed method aims to biomimetic complete mouth-gastric-intestinal system basing on an adaptation of the unified bioaccessibility method (UBM) modified by the inclusion of a dialysis membrane to mimic intestinal absorption and obtain the orally bioavailable fractions. It was followed by a vortex-assisted liquid-liquid extraction (VALLE) step, using gas chromatography-tandem mass spectrometry (GC–MS/MS). Analytical procedure was effectively validated by employing selected reaction monitoring (SRM) mode in MS/MS, matrix-matched calibration, and deuterium-labelled surrogate standards. This approach ensured heightened sensitivity, minimized matrix effects, and compensated for any losses during the process. The validation process covered various aspects, including studying linearity, determining detection and quantification limits, assessing analytical recoveries at three concentration levels, and evaluating precision both within a single day and across multiple days. The validated method was applied to PM 10 samples, revealing that polycyclic aromatic hydrocarbons (PAHs) were the most frequently detected, with significant seasonal variations in their concentrations. Organophosphorus flame retardants (OPFRs) like TCPP were also detected in bioavailable fractions, highlighting their potential health impact. Bisphenols, SMCs, and PAEs were not detected, suggesting low levels in the studied urban area. Further research is needed to understand the bioavailability of PM-bound pollutants in different environments. [ABSTRACT FROM AUTHOR]

• Enhanced Sensitivity: achieved low LODs and interference-free electropherograms. • Clinical Applicability: successfully analyzed human serum samples. • Innovative Methodology: integrated UA-DLLME and LVSS for analysis of two pairs of barbiturate enantiomer drugs. • Sensitivity Boost: attained a 6200–6400-fold sensitivity enhancement. • Efficient Analysis: provided a simple, high-efficiency method for biosample analysis. A rapid, straightforward, and sensitive approach to quantifying enantiomeric barbiturates in serum was developed by integrating ultrasound-assisted dispersive liquid–liquid microextraction (UA-DLLME) with large-volume sample stacking (LVSS) in capillary electrophoresis (CE). UA-DLLME was employed for sample preparation, and on-column preconcentration by using LVSS with polarity switching was implemented to enhance sensitivity. We thoroughly investigated and optimized various parameters influencing extraction and stacking to achieve optimal detection performance with the highest enrichment efficiencies. Under optimal extraction conditions (injection of a mixed solution containing 40 μL of CHCl 3 and 200 μL of tetrahydrofuran into 1 mL of a sample solution at pH 10.0), LVSS was performed using 600 mM Tris-boric acid (pH 9.5) containing 35 mM hydroxypropyl-β-cyclodextrin and sodium taurodeoxycholate hydrate. A voltage of 20 kV was applied and a preinjection water plug was loaded at a height of 25 cm for 10 s. Subsequently, the sample solution was injected at a height of 25 cm for 480 s, after which a voltage of −20 kV was applied and the sample stacking was initiated. The stacking process was completed when 95 % of the separation current was attained. Under optimized conditions, the contraction folds of the four barbiturate analytes (R, S -Secobarbital, R, S -pentobarbital) were improved by approximately 6400-fold, achieving detection limits of 0.1 ng/mL. The limits of quantification for all analyte enantiomers were 0.5–50 ng/mL, demonstrating good linearity (r > 0.997). Migration times exhibited a relative standard deviation of less than 1.7 %, whereas peak areas for the four analytes exhibited a deviation of 8.7 %. Finally, the established method was effectively applied to the analysis of human serum samples. [ABSTRACT FROM AUTHOR]

• Method developed for PFAS in various food matrices. • Limit of quantification for 4 regulated EFSA PFAS in the lower ng/kg range achieved. • The method can also be used for food contact materials. • The method was applied to food contact material, seaweed samples, eggs and milk. Dietary intake is the major pathway of human exposure to per- and polyfluoroalkyl substances (PFAS). Due to their generally very low concentrations in food, especially for foods of plant origin, and their toxicological relevance, demand is growing for improved selective and sensitive analytical methods for the determination of PFAS in the lower ng/kg range. The relevance is pointed out due to the fact that the European Commission has published limits of quantification (LOQs) in the lower ng/kg range for different food matrices in Recommendation (EU) 2022/1431 on the monitoring of perfluoroalkyl substances in food. For example, LOQs of 2 ng/kg for perfluorooctanesulfonic acid (PFOS), 1 ng/kg for perfluorooctanoic acid (PFOA), 1 ng/kg for perfluorononanoic acid (PFNA) and 4 ng/kg for perfluorohexanesulfonic acid (PFHxS) in fruit, vegetables and baby foods are required. A new, very sensitive method is presented here for the determination of 22 PFAS in food and food contact materials. The method is based on liquid-solid extraction and automated clean-up using two solid phase extraction techniques. The analytes are separated and detected by HPLC-MS/MS. A limit of detection (LOD) of 0.33 ng/kg and an LOQ of 1.0 ng/kg are attained for plant foods such as fruits and vegetables as well as for milk and baby food. For foods of animal origin such as egg, meat, fish and paper-based food contact materials an LOD of 1.6 ng/kg as well as an LOQ of 5.0 ng/kg are attained. PFOS and PFOA were the most abundant compounds in the food samples with concentration as high as 1,051 ng/kg of PFOA in sea weed samples and 772 ng/kg of PFOS in eggs samples. In food contact material samples, higher levels were found with a maximum of 310,000 ng/kg PFHxA. In sum the presented method firstly allows determination of PFAS in a wide variety of foodstuffs and paper-based food contact materials at EU-required concentration ranges. [ABSTRACT FROM AUTHOR]

• Innovative integration of magnetic ionic liquids (MILs) with dispersive liquid-liquid microextraction (DLLME) for PBDE analysis. • Synergistic application of Py-GCMS– for comprehensive sample analysis. • Precise optimization of DLLME parameters through central composite design (CCD). • Successful detection and quantification of PBDEs in sewage sludge samples. This study addresses the analysis of emerging contaminants, often using chromatographic techniques coupled to mass spectrometry. However, sample preparation is often required prior to instrumental analysis, and dispersive liquid-liquid microextraction (DLLME) is a viable strategy in this context. DLLME stands out for its ability to reduce sample and solvent volumes. Notably, dispersive liquid-liquid microextraction using magnetic ionic liquids (MILs) has gained relevance due to the incorporation of paramagnetic components in the chemical structure, thereby eliminating the centrifugation step. A pyrolizer was selected in this work to introduce sample onto the GC column, since the MIL is extremely viscous and incompatible with direct introduction through an autosampler. This study is the first to report the use of a DLLME/MIL technique for sample introduction through a pyrolizer in gas chromatography coupled to mass spectrometry (GC–MS). This approach enables the MIL to be compatible with gas chromatography systems, resulting in optimized analytical and instrument performance. The analysis of polybrominated diphenyl ether flame retardants (PBDEs) was focused on the PBDE congeners 28, 47, 99, 100, and 153 in sewage sludge samples. The [P 6,6,6,14 +] 2 [MnCl 4 2−] MIL was thoroughly characterized using UV–Vis, Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy, as well as thermal analysis. In the chromatographic method, a pyrolyzer was used in the sample introduction step (Py-GC–MS), and critical injection settings were optimized using multivariate approaches. Optimized conditions were achieved with a temperature of 220 °C, a pyrolysis time of 0.60 min, and an injection volume of 9.00 μL. DLLME optimization was performed through central compound planning (CCD), and optimized training conditions were achieved with 10.0 mg of MIL, 3.00 μL of acetonitrile (ACN) as dispersive solvent, extraction time of 60 s, and volume of a sample of 8.50 mL. Precision was observed to range from 0.11 % to 12.5 %, with limits of detection (LOD) of 44.4 μg L−1 for PBDE 28, 16.9 μg L−1 for PBDE 47 and PBDE 99, 33.0 μg L−1 for PBDE 100 and 375 μg L−1 for PBDE 153. PBDE 28 was identified and analyzed in the sludge sample at a concentration of 800 μg L−1. The use of MIL in dispersive liquid-liquid microextraction combined with pyrolysis gas chromatography-mass spectrometry enables identification and quantification of PBDEs in sewage sludge samples at concentrations down to the µg L−1 level. [ABSTRACT FROM AUTHOR]

• 11 free fatty acids were simultaneously determined by LC-MS/MS. • Microvolume serum pretreated by two-step derivatisation strategy. • High throughput analysis of samples can be achieved. • Method was developed and validated with good results. A stable isotope dilution–liquid chromatography–tandem mass spectrometry method based on a derivatisation strategy involving an N,N'-carbonylimidazole solution (CDI) with 4-(dimethylamino)-benzenemethanamine was developed for the determination of 11 free fatty acids (FFAs) in human blood samples. Serum samples were subjected to liquid‒liquid extraction and centrifuged, and the supernatant was collected for a two-step derivatisation reaction with a CDI and 4-(dimethylamino)-aniline acetonitrile solution. The derivatised solution was separated on a ACQUITY UPLC HSS T3 column (2.1 × 50 mm, 1.8 µm) column with a mobile phase consisting of water–acetonitrile in gradient elution and then detected by tandem mass spectrometry using electrospray ionisation (ESI) and multiple reaction monitoring (MRM) in positive ion mode and quantified using the isotope internal standard method. The effects of the derivatisation reaction time, temperature and concentration of derivatisation reagents on the response values of the analytes were investigated. The optimal conditions were as follows: 1.0 mg mL−1 CDI acetonitrile solution at 25 °C for 25 min, followed by a reaction with a 1.0 mg mL−1 4-(dimethylamino)-benzenemethanamine acetonitrile solution at 70 °C for 30 min. Under the optimal conditions, the limits of detection (LODs) of the 11 FFAs were in the range of 3.0–14.0 ng mL−1; the limits of quantification (LOQs) were in the range of 8.0–45.0 ng mL−1; and the mean recoveries ranged from 83.4 to 112.8%, with intraday and interday precisions ranging from 0.7 to 9.1% and 3.7–9.5%, respectively. The experimental method is simple in terms of the pretreatment operation, accurate and reliable, and can be applied to the sensitive determination of FFAs in human blood samples. [ABSTRACT FROM AUTHOR]

• DES-based DLLME as a greener alternative for analytes preconcentration. • Camphor:Hexanoic acid (1:1) resulted in suitable performance for the most analytes. • The proposed method was applied to a certified reference material of soybeans. • Plackett-Burman design was used to identify the critical sample preparation variables. • AGREE metric system showed a certain greenness of the proposed method. A reliable and greener alternative to the usual extraction methods is reported for the determination of pesticide residues in soybeans. This novel approach combines the classical QuEChERS extraction method with a DLLME (dispersive liquid-liquid microextraction) step, utilizing a deep eutectic solvent (DES) - camphor: hexanoic acid (1:1 molar ratio) - as the microextraction solvent. This DES has never been employed in pesticide analysis by gas chromatography-mass spectrometry of complex matrices like soybeans. A Plackett-Burman screening design was employed to optimize sample preparation variables of QuEChERS (amount of sodium chloride and magnesium sulfate, and amount of PSA and C18 sorbents) and DLLME (pH of medium, amount of sodium chloride, and volume of microextraction solvent). This design allowed for a systematic evaluation of the impact of each parameter on the method's performance. The optimized method was evaluated using a certified reference material and commercial samples of soybeans. The method exhibited high accuracy and precision for most of the analytes under study, demonstrating its applicability for pesticide residue analysis in soybeans. To assess the greenness and practicality of the developed method, the Analytical Greenness (AGREE) and Blue Applicability Grade Index (BAGI) metric systems were employed, respectively. Overall, the proposed QuEChERS-DLLME method using a DES solvent is a reliable and greener alternative to conventional extraction methods for the determination of pesticide residues in soybeans. Its high performance, coupled with its environmental friendliness, makes it a promising tool for food safety analysis. [ABSTRACT FROM AUTHOR]

• Good determination of 20 antihistamines was obtain at 8 min by UHPLC. • Dispersive micro solid phase extraction is efficient for extracting antihistamines. • Compared with existing methods, this method showed lower LODs. • Results of antihistamines in milk shown maybe be noteworthy issues for human. Ultrahigh-performance liquid chromatography coupled with high-field quadrupole Orbitrap high resolution mass spectrometry was used for the separation and determination of 20 antihistamines, and a dispersive micro solid-phase extraction procedure using high-performance absorbing material was developed as a sample preparation strategy for extracting 20 antihistamines from milk. Instrument conditions and key parameters influencing extraction efficiency were investigated to obtain an optimized method. The limit of detection for 20 antihistamines in milk using this method is 0.05 µg/L to 1.0 µg/L. Recoveries are between 80.7 % and 108.3 %, and the relative standard deviation is less than 15 %. It is suitable for confirmatory monitoring and quantitative analysis of 20 antihistamines in milk. The results show that antihistamines in milk may be noteworthy issues for human health and environmental pollution. [ABSTRACT FROM AUTHOR]

• Novel biomonitoring method for urinary pesticide metabolites. • Validated method with low detection limits and easy to implement. • Unveiled association between pesticide exposure and oxidative stress in preschool children. • Para-nitrophenol significantly contributed to elevated oxidative stress levels. Investigating pesticide exposure and oxidative stress in preschool children is essential for elucidating the determinants of environmental health in early life, with human biomonitoring of urinary pesticide metabolites serving as a critical strategy for achieving this objective. This study demonstrated biomonitoring of 2 phenoxyacetic acid herbicides, 2 organophosphorus pesticide metabolites, and 4 pyrethroid pesticide metabolites in 159 preschool children and evaluated their association with oxidative stress biomarker 8-hydroxydeoxyguanosine. An enzymatic deconjugation process was used to release urinary pesticide metabolites, which were then extracted and enriched by supported liquid extraction, and quantified by ultra-high performance liquid chromatography-tandem mass spectrometry with internal standard calibration. Dichloromethane: methyl tert‑butyl ether (1:1, v/v) was optimized as the solvent for supported liquid extraction, and we validated the method for linear range, recovery, matrix effect and method detection limit. Method detection limit of the pesticide metabolites ranged from 0.01 μg/L to 0.04 μg/L, with satisfactory recoveries ranging from 70.5 % to 95.5 %. 2,4,5-Trichlorophenoxyacetic acid was not detected, whereas the other seven pesticide metabolites were detected with frequencies ranging from 10.1 % to 100 %. The concentration of urinary pesticide metabolites did not significantly differ between boys and girls, with the median concentrations being 9.39 μg/L for boys and 4.90 μg/L for girls, respectively. Spearman correlation analysis indicated that significant positive correlations among urinary metabolites. Bayesian kernel machine regression revealed a significant positive association between urinary pesticide metabolites and 8-hydroxydeoxyguanosine. Para-nitrophenol was the pesticide metabolite that contributed significantly to the elevated level of oxidative stress. [ABSTRACT FROM AUTHOR]

• Modification of cellulose paper by in situ synthesis of metal-organic framework-5. • Bonding between functional groups on cellulose paper with organic ligand. • Cellulose/MOF-5 was used in the thin film solid-phase microextraction method. • Thin film showed a good ability to extraction of selective drugs in urine samples. • The method is effective, sensitive, cost-effective and have wide LDRs and low LODs. This work, reports the successful preparation a thin film by a simple and inexpensive process for quantification of a model analytes in the urine sample using HPLC-UV. To this end, cellulose paper was employed as a substrate for the in-situ synthesis of MOF-5, to increase the resistance of the prepared film. The prepared film can be reused 26 times with no reduction in its performance. The thin film prepared by MOF-5 modified cellulose substrate was utilized in thin film microextraction (TFME) method for the extraction and preconcentration of naproxen, aspirin, tolmetin, and celecoxib. Under optimal conditions, the linear dynamic range of the target analytes was 2–500 µg L −1 with correlation coefficients (R2) ranging from 0.9961 to 0.9990. Also, the limits of detection (LODs), the limits of quantification (LOQs) and relative standard deviation (RSD%) of the proposed method for selected analytes ranged between 0.57 and 0.77 µg L −1, 1.7 to 2.3 and 3.5 % to 6.2 %, respectively. Moreover, relative recoveries varied from of 94 % to 108 %, indicating the absence of matrices effect in the proposed method. Eventually, the TFME was successfully used for the extraction of selected analytes from urine samples. [ABSTRACT FROM AUTHOR]

• The DLLME-BE method enriches the dalbergia odorifera components in xiangdan injection. • The bar-form-diagram provides a more comprehensive reflection of the material foundation. • CRITIC-TOPSIS is proposed for quantitatively describe the multi-criteria optimization issue. • 29 components are characterized as the pharmaceutical foundation of XDI. Xiangdan Injection are commonly used traditional Chinese medicine formulations for the clinical treatment of cardiovascular diseases. However, the trace components of Dalbergia odorifera in Xiangdan Injection pose a challenge for evaluating its quality due to the difficulty of detection. This study proposes a technology combining dispersive liquid-liquid microextraction and back-extraction (DLLME-BE) along with Bar-Form-Diagram (BFD) to address this issue. The proposed combination method involves vortex-mixing tetradecane, which has a lower density than water, with the sample solution to facilitate the transfer of the target components. Subsequently, a new vortex-assisted liquid-liquid extraction step is performed to enrich the components of Dalbergia odorifera in acetonitrile. The sample analysis was performed on HPLC-DAD, and a clear overview of the chemical composition was obtained by integrating spectral and chromatographic information using BFD. The combination of BFD and CRITIC-TOPSIS strategies was used to optimize the process parameters of DLLME-BE. The determined optimal sample pre-treatment process parameters were as follows: 200 μL extraction solvent, 60 s extraction time, 50 μL back-extraction solvent, and 90 s back-extraction time. Based on the above strategy, a total of 29 trace components, including trans-nerolidol, were detected in the Xiangdan Injection. This combination technology provides valuable guidance for the enrichment analysis of trace components in traditional Chinese medicines. [ABSTRACT FROM AUTHOR]

• Novel device for extracting substances from a chromatographic plate. • Simple, cost-effective, reliable solid-liquid phase extraction method. • The extraction method ensures no cross-contamination between samples occurs. • Sample preparation technique for LC-MS analysis of coccidiostats. A new approach to extracting substances from a spot on a chromatographic plate for subsequent liquid chromatography-mass spectrometry analysis is described. This method involves extraction in a solid phase (an adsorbent layer of a chromatographic plate) - a liquid system using a simple device. For a single extraction of six selected coccidiostats from the adsorbent layer on the chromatographic plate with silica gel, 50 µL of methanol was used for 5 min. The data from the extraction experiments and liquid chromatography-mass spectrometry measurements demonstrated a good correlation between the ratio of the peak areas of the coccidiostats to the internal standard and the concentration of the substances in the range of two orders of magnitude. The coefficients of determination for the mentioned correlations range from 0.962 to 0.999. Moreover, the repeatability and reproducibility, expressed as the percentage values of relative standard deviation, do not exceed 7.5 % for any of the coccidiostats. [ABSTRACT FROM AUTHOR]

• Quantitative data from parallel artificial liquid membrane extraction are reliable. • High accuracy and precision were obtained from multiple sources of plasma. • High accuracy and precision were obtained with different operators. • High accuracy and precision were obtained under non-exhaustive conditions. • Stable isotopically labelled internal standards are recommended. The use of miniaturized systems with the possibility for automation has become increasingly popular in the field of bioanalysis. As a new approach to liquid phase microextraction in the 96-well format, parallel artificial liquid membrane extraction (PALME) was introduced in 2013. In the present work, the reliability of the quantitative data obtained with PALME was thoroughly evaluated. Amitriptyline, nortriptyline, quetiapine, venlafaxine, o-desmethylvenlafaxine, and fluoxetine were selected as model analytes. The analytes were extracted under non-exhaustive conditions from human plasma samples and the extracts were analyzed directly by LC-MS/MS. Accuracy was within ±15% and precision was <15% when the QC samples were prepared in both pooled plasma and in plasma from multiple sources. Accuracy and precision was superior when stable isotopically labelled (SIL) internal standards were used, as compared to structural analogue internal standards in the plasma samples from multiple sources. SIL internal standards are therefore recommended as the first choice. Assessment of accuracy and precision was also carried out with four different operators performing the extraction procedure, providing accuracy within ±15% and precision <15%. The extraction recoveries were in the range from 48 to 85 %, and non-exhaustive extraction of the analytes did not affect the accuracy and precision of the method. With the method described, up to 96 samples can be extracted with a total extraction time of 60 min and with a total consumption of organic solvent less than 0.4 mL for the whole wellplate. PALME is therefore a new approach to high-throughput sample preparation, providing accurate quantification, along with simple workflow, low consumption of organic solvent, and extensive sample clean-up. [ABSTRACT FROM AUTHOR]

• A simple, green and sensitive method for 17 phenolic compounds determination was proposed. • This method was based on SULLE pretreatment and HPLC-ECD quantification technique. • The SULLE method provided high extraction efficiency and consumed very little solvent and time. • The HPLC-ECD technique provided excellent sensitivity and selectivity. • The method was successfully applied for analysis of honey with different floral origin. In this work, a simple sugaring-out assisted liquid-liquid extraction (SULLE) method coupled with high performance liquid chromatography-electrochemical detection (HPLC-ECD) has been developed for rapid and sensitive determination of 17 phenolic compounds in honey. To achieve the maximum extraction efficiency of target analytes, several parameters, such as pH, ionic strength, extraction times and the volume of extracting solvent were optimized. Chromatographic separation was performed on a C18 column with a gradient methanol/aqueous formic acid elution, and the ECD was set at 1.0 V in oxidative mode. Under the optimal conditions, good linearity was obtained for 17 phenolic compounds with the coefficients of determination (R 2) higher than 0.9986 in the range of 0.05–20 μg mL–1. The limits of detection (LODs, S/N = 3) for the 17 phenolic compounds were in the range of 0.20–1.26 μg kg–1 by ECD, 9–83 times lower than those obtained with UV detection. Satisfactory recoveries between 79.8% and 105.7% were obtained for spiked honey samples with relative standard deviations (RSD) less than 5.1%. Compared with conventional LLE method, the proposed SULLE method provided higher extraction efficiency and had advantages of rapidity, ease of operation, much less consumption of organic solvents and samples. The proposed HPLC-ECD method featuring excellent sensitivity and selectivity has been applied to the quantification of phenolic compounds in honey samples of different floral origin. [ABSTRACT FROM AUTHOR]

• Pretreatment procedures are optimized for HPLC-MS/MS detection of isoprenoids. • The first report on releasing algal isoprenoids by NaOH for quantitative analysis. • Isoprenoids are depleted by carotenogenesis while accumulated in the dark. Isoprenoid diphosphates are important precursors actively participating in many downstream metabolisms; they are often in modified forms, e.g. , protein-coupled or esterified form. Therefore, in vivo level of free isoprenoid diphosphates is quite low, ˜0.07 nmol/g fresh weight in plants. In order to directly measure the isoprenoid diphosphate pool during stress-induced accumulation of astaxanthin in Haematococcus pluvialis , the present study optimized several pretreatment procedures to enrich free isoprenoid diphosphates for high-pressure liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) detection. Specifically, different extraction solvents, e.g. , water, methanol, chloroform, and mixture of water, methanol, and chloroform (1:1:1, V/V/V), and solid phase extraction (SPE) columns (OASIS@ WAX and HLB Cartridges) were compared; and gentle decoupling by NaOH or trifluoroacetic acid (TFA) was introduced to release free isoprenoid diphosphates. Results found that solvent mixture of water, methanol and chloroform (1:1:1, V/V/V) showed the highest extraction efficiency (R E) for five isoprenoid diphosphates, ranging from 76.83% to 92.43%; HLB column showed the balanced recoveries ranging from 75.29% to 87.54%; and incubation with low NaOH (˜4.7 mmol/L) at 4 °C significantly increased detectable isoprenoid diphosphates in algal cells, some of which were undetectable or in trace level before NaOH decoupling. The method was applied to H. pluvialis cells under various stresses. Low levels of isoprenoid diphosphates were determined in most of the stresses used, e.g. , 0.19 ± 0.09 to 0.98 ± 0.06 mg/g fresh weight (FW) for IPP/DMAPP, 0.35 ± 0.07 mg/g FW for GGPP and undetectable for FPP and GPP; while isoprenoid diphosphates were significantly accumulated in the dark to 3.27 ± 0.05, 0.17 ± 0.09, 1.81 ± 0.16 and 0.58 ± 0.07 mg/g FW for IPP/DMAPP, GPP, FPP and GGPP, respectively. These results implied that isoprenoid diphosphates were exhausted by downstream carotenogenesis under stress. Our work emphasizes NaOH decoupling for exact quantitation of in vivo isoprenoid diphosphates. [ABSTRACT FROM AUTHOR]

Highlights • Development of HPTLC method for the determination of quinalphos in human whole blood. • Optimization of extraction procedure. • Recovery of 93.61% was achieved from diethyl ether extract at pH 3. • Bioanalytical method validation of HPTLC method. • Application of developed procedure in three fatal cases of poisoning. Abstract A simple and rapid procedure for the determination of quinalphos in human whole blood using liquid-liquid extraction and high-performance thin-layer chromatography was developed and validated. Seven different organic solvents were tested for optimum extraction of quinalphos from spiked blood samples. The effect of pH on the extraction yield of quinalphos was also examined. An average recovery of 93.61% was achieved from diethyl ether solvent at pH 3. Chromatographic separation was performed on silica gel 60F 254 plates using mobile phase n -hexane-acetone in the ration 9:1 (v/v). Densitometric detection was carried out at 325 nm in absorbance mode. The interference of other organophosphorus pesticides of forensic relevance was not observed. The linear regression analysis in spiked whole blood samples resulted in linear calibration plot in the range 1 to 100 μg mL–1 with r2 = 0.9981. Sensitivity was represented by LLOQ at 1 μg mL–1. The within-day precision and between-day precision ranged from 0.18 to 1.04%, and 0.14 to 0.79% with an overall average recovery of 91.06% at three concentrations 1, 10, and 50 μg mL–1. No significant decrease in the concentration of quinalphos was observed for samples under different storage conditions. Finally, the developed procedure was applied to postmortem blood samples obtained in three fatal cases of poisoning by quinalphos. [ABSTRACT FROM AUTHOR]

• Efficient separation of actinides from HLW will help in nuclear waste management. • Separation of long-lived actinides from nuclear waste is extremely challenging. • TAM-3-DGA and TAM-4-DGA (multi-podal DGA) are promising ligands for actinides. • Use of RTILs in EXC enhanced the extraction efficiency of ligands several folds. • Two new EXC resins were prepared using TAM-3-DGA and TAM-4-DGA containing RTIL. Two new extraction chromatographic resins (ECRs) were prepared by impregnating two exotic diglycolamide (DGA) ligands (having three or four DGA moieties tethered to aza-crown ether scaffolds) dissolved in an ionic liquid onto an inert solid support. A room temperature ionic liquid (RTIL) was used for enhancing the performance of the ECRs. The ECR containing triaza-9-crown-3 functionalized with three DGA moieties (TAM-3-DGA), and tetraaza-12-crown-4 tethered with four DGA arms (TAM-4-DGA) were evaluated for the separation of Am3+ and Pu4+from nitric acid solutions. The resin capacity for Eu3+ was 9.52 mg/g and 7.24 mg/g for TAM-3-DGA and TAM-4-DGA resins, respectively. Similarly, the resin capacity for Pu4+was 7.44 mg/g and 5.72 mg/g for TAM-3-DGA and TAM-4-DGA resins, respectively. These maximum loading values corresponded to the formation of a 1:1 metal/ligand complex for the Eu3+ ion and a 1:2 metal/ligand complex for the Pu4+ ion. The sorption of Eu3+and Pu4+on the resins followed a chemisorption phenomenon on both resins. The sorbed Eu3+and Pu4+ions from the resin phase could be efficiently desorbed with complexing ligands such as guanidine carbonate/HEDTA and oxalic acid, respectively. [ABSTRACT FROM AUTHOR]

• The SUPRAS prepared by 1-octanol and THF was used for the extraction of coumarins. • The composition, viscosity, structure and micromorphology of SUPRAS were studied. • The extraction mechanism of SUPRAS was explored by inverted fluorescence microscope. • The extraction conditions were optimized using OFAT, RSM and ANN-GA. • In present method, less extraction time and extraction solvent were consumed. A simple, fast, and efficient ultrasonic-assisted supramolecular solvent microextraction combined with high performance liquid chromatography method was developed for the determination of coumarins in Cortex fraxini , including esculin, esculetin and fraxetin. In this study, a novel supramolecular solvent was prepared with 1-octanol, tetrahydrofuran and water for the first time, and its composition, viscosity, density, structure, and micromorphology were characterized. The prepared supramolecular solvent exhibited vesicular structures and had the characteristics of low viscosity. Through single-factor experiments, response surface methodology and artificial neural network-genetic algorithm, the optimal extraction conditions were obtained as follows: NaCl concentration of 1 mol mL−1, pH value of 10, solid-liquid ratio of 10:1, vortex time of 30 s, ultrasonic power of 100 W, ultrasonic temperature of 60 °C, ultrasonic time of 15 min, centrifugation speed of 5000 rpm, and centrifugation time of 1 min. The results demonstrated that the artificial neural network model exhibited maximum R -values of 0.98703, 0.97440, 0.99836, and 0.95447 for training, testing, validation, and all dataset, respectively. The minimum mean square errors were 0.75, 10.15, 1.99, and 2.63, respectively. This indicated that the predicted values were almost consistent with the actual values. Under the optimal conditions, the total extraction yields of target analytes reached 2.80 %. The calibration curves for each analyte exhibited excellent linearity within the linear range (r > 0.9993). The limits of detection and quantification ranged from 4.87 to 6.55 ng mL−1 and 16.24 to 21.84 ng mL−1, respectively. The recoveries ranged from 98.71 % to 111.01 % with relative standard deviations of less than 3.6 %. The present method had the advantages of short extraction time (15 min) and less solvent consumption (0.5 mL). The prepared supramolecular solvent was proved to have great potential in extracting coumarins from medicinal plants. [ABSTRACT FROM AUTHOR]

• PDDA/MWCNTs thin films were easily prepared via LBL on borosilicate bottles. • Bottles were used to extract analytes with diverse physical chemical properties. • Sorbent material exhibited high efficiency applied to different complex samples. • LBL films showed outstanding extraction (up to 92 %) and sorption capabilities. • The developed approach enables a cost-effective, reusable compound extraction. This article presents the assembly and characterization of poly(diallyldimethylammonium chloride)/multi-walled carbon nanotubes (PDDA/MWCNTs) thin films on borosilicate bottles using a layer-by-layer (LBL) approach. The thin films, consisting of 10 bilayers of coating materials, were thoroughly characterized using UV-VIS spectroscopy, scanning electron microscopy (SEM), and zeta potential measurements. The modified bottles were then utilized for the extraction of analytes with diverse acid-base characteristics, including drugs, illicit drugs, and pesticides, from saliva, urine, and surface water samples. The studied analytes can be adsorbed on the surface of the LBL film mainly through hydrogen bonding and/or hydrophobic interactions. Remarkably high extraction percentages of up to 92 % were achieved, accompanied by an impressive enhancement in the analytical signal of up to 12 times when the sample volume was increased from 0.7 to 10 mL. These results highlight the outstanding extraction and sorption capabilities of the developed material. Additionally, the (PDDA/MWCNTs) 10 films exhibited notable resistance to extraction and desorption processes, enabling their reuse for at least 5 cycles. The straightforward and cost-effective fabrication of these sorbent materials using the LBL technique, combined with the ability to extract target compounds during sample transportation and/or storage, renders this sample preparation method a promising alternative. [ABSTRACT FROM AUTHOR]

• Sol-gel Carbowax 20M/IL-based absorbent was fabricated for the extraction of lanreotide. • The CPME platform was found to be reusable at least 20 times. • The composite sorbent eliminates the necessity of the matrix pH adjustment. In this research, a sol-gel Carbowax 20M-zwitterionic ionic liquid composite sorbent-based capsule phase microextraction (CPME) device was developed in combination with liquid chromatography-post column derivatization for the first ever reported determination of a somatostatin analogue – lanreotide in human urine. The sol-gel Carbowax 20M-zwitterionic ionic liquid composite sorbent was encapsulated in the lumen of a polypropylene capillary tube and characterized by FT-IR spectroscopy and SEM with energy dispersive X-ray spectroscopy (EDS). The main steps of the CPME workflow were optimized to obtain high extraction efficiency for the target analyte. After the separation of the analyte on a C 8 stationary phase, the peptide was derivatized online with o -phthalaldehyde before the fluorescence detection. The main experimental parameters of CPME and the post-column procedures were systematically investigated and optimized. The method was validated in terms of selectivity, linearity, accuracy, precision, limits of detection (LOD), and limits of quantification (LOQ). The relative bias ranged between 88.8 and 115.6 % for the peptide, while the RSD values for repeatability and intermediate precision were less than 14.3 %. The achieved limit of detection (LOD) was 0.2 μΜ while the limit of quantitation (LOQ) was established as 0.9 μΜ. Finally, the sol-gel Carbowax 20M-zwitterionic ionic liquid composite sorbent-based microextraction capsules were found to be reusable for at least 20 extractions. The developed method presented adequate overall performance, and it could be applied in the analysis of selected peptide in human urine samples. [ABSTRACT FROM AUTHOR]

• Novel dual optical detectors approach for analyses of phenol and nine derivatives in water samples. • Two-step LLE was used for sample treatment with enrichment factors up to 1120-fold. • CE-LEDIF was utilized to determine phenol, chlorophenols, and methyl phenols in channel 1. • CE-UV in channel 2 was used for analyzing nitrophenols. • The method detection limits of 10 phenol compounds were lowered to 0.02–0.60 µg/L. In this research, the analytical method was developed and evaluated for determining phenol and its nine derivatives belong to the US EPA priority pollutant list in water samples by using dual-channeled capillary electrophoresis (CE) coupled with two types of optical detectors, namely LED-induced fluorescence (LEDIF) and ultraviolet (UV) detectors. The optimal background electrolytes for the first and second CE channels were 20 mM borate (pH 9.80) with 400 µM fluorescein and 55 mM borate (pH 11.75), respectively. The two-step liquid-liquid extraction (LLE) was used for sample preparation and enrichment, in which phenol and its derivatives were extracted from the aqueous phase using 10 mL of n-hexane/1-octanol (60/40, v/v) and then were back extracted into a 0.1 M NaOH as a final acceptor phase. Under the optimal CE and two-step LLE conditions, the enrichment factors of 10 phenols were 184 – 1120-fold, and the method detection limits were lowered to 0.02–0.60 µg/L. The obtained intra-day and inter-day precisions in terms of relative standard deviations (RSD) were between 4.0 and 7.3 % and 6.7 and 14 %, respectively. This approach was used to determine phenols in water samples, with recoveries ranging from 82.0 to 108.9 %. In combination with sample enrichment by two-step LLE extraction, this is the first CE study conducted to determine phenols in the EPA list using two detector approaches, specifically CE-LEDIF/CE-UV. [ABSTRACT FROM AUTHOR]

• A novel UHPLC-MS/MS method was developed for the analysis vitamin K. • A simple extraction technique based on miniaturized LLE was used. • Ultracentrifugation for the separation of lipoprotein fractions was included. • Four forms of vit. K were analyzed in human and rat serum and lipoprotein fractions. Determination of the various forms of vitamin K, which are involved in coagulation and other physiological processes in humans, is challenging and no standardized method is yet available. Therefore, a reliable and practical method was developed to quantify vitamin K levels in serum and additionally in lipoprotein fractions to clarify its distribution. The LC-MS/MS method for the determination of vitamin K 1 and the three main isoforms of vitamin K 2 (MK-4, MK-7, MK-9) was combined with a gradient ultracentrifugation technique to allow the separation of lipoprotein fractions. The chromatographic separation was carried out on a Kinetex™ C18 column using a mobile phase consisting mainly of methanol. The target analytes were detected by electrospray ionization mass spectrometry. The separation of all four substances was achieved after a simple sample preparation technique based on miniaturized liquid-liquid extraction. Our method of only 8.5 min revealed the levels of the major forms of vitamin K in 59 human and 12 rat sera and confirmed our hypothesis that vitamin K is primarily (about 50 %) found in the high-density lipoprotein fraction. The median concentrations of vitamin K 1 , MK-4, MK-7, and MK-9 were found to be 1.19, 2.98, 0.43, and < 0.71 nmol/L in human serum and 1.74, 6.75, less than 0.2, and less than 0.5 nmol/L in rat serum, respectively. [ABSTRACT FROM AUTHOR]

• Established a detection method for 106 pesticides in livestock urine. • Comparison of two rapid purification: Captiva EMR-Lipid and QuEChERS. • Selected three adsorbents (C 18 , PEP, and PSA) from 20 materials for QuEChERS. • Acid-base conversion of the sample extraction environment improved the recovery. • Eight pesticides were detected and risk assessed in livestock urine. The establishment of an analytical method for pesticide residues in livestock urine can realize the real-time monitoring of pesticide pollution in livestock breeding. In this study, a novel method was developed for the determination of 106 pesticide residues in livestock urine based on a modified QuEChERS extraction and liquid chromatography–tandem mass spectrometry. Acetonitrile was used to extract target analytes through acidic and alkaline switching of the sample environment. The purification effect of captiva EMR-Lipid on samples was investigated. Three kinds of materials, C 18 , polar enhanced polymer (PEP), N-propylethylenediamine (PSA), were selected from 20 kinds of materials as adsorbents for QuEChERS. A mass analysis was carried out using simultaneous scanning in both positive and negative ion mode and multiple reaction monitoring mode. All analytes showed good linearity, with correlation coefficients (R 2) greater than 0.9923; their limits of quantification were 0.02–1.95 ng/mL. The average recoveries at low, medium, and high spiked levels were in the range of 70.1 %–117.3 %, with intra-day precision ranging from 3.4 % to 16.9 % and inter-day precision ranging from 4.0 % to 19.3 %. The established analytical method was used to analyze the pesticide residue in swine urine and bovine urine collected from farms in Yining, Xinjiang, China. A total of 8 pesticides were detected, and the residue ranged from less than the limit of quantitation to 22.4 ng/mL. The top three pesticides with the highest detection frequency were clothianidin, thiamethoxam, and dinotefuran. The exposure assessment based on the monitored pesticide residue concentration levels showed that the detected pesticides could pose little risk to cattle and pigs. [ABSTRACT FROM AUTHOR]

• First characterization and comparison of saponins across 6 Bupleurum species. • Generation of a predicted saikosaponin database using MATLAB as PIL. • MATLAB automated creation of annotation lists to filter false positive ions. • Positive/negative ionization workflows for accurate saikosaponin characterization. • 707 saikosaponins identified from 2 authentic Radix Bupleuri and 4 adulterants. Comprehensive and rapid analysis of secondary metabolites like saponins remains challenging. This study aimed to establish a semi-automated workflow for filtration, identification, and characterization of saikosaponins in six Bupleurum species. Radix Bupleuri, a high-sales herbal medicine, is often adulterated, restricting its quality control and applications. Two authentic Radix Bupleuri species and four major adulterants were analyzed through UHPLC-LTQ-Orbitrap-MS for targeted saikosaponin analysis. To reveal trace saikosaponins and obtain quality fragment data, a MATLAB-based process automatically enumerating "sugar chain + aglycone + side chain" combinations and deduplicating generated a predicted saikosaponin database covering all possible saikosaponins as a precursor ion list for comprehensive targeted acquisition. To focus on informative ions and reduce MS analysis workload, we utilized MATLAB to automatically filtrate the false positive ions by MS1 and MS2 spectrometry. The newly established MATLAB-assisted data acquisition approach exhibited 50 % improvement in characterization of targeted saikosaponins. Furthermore, positive and negative ionization workflows were designed for accurate saikosaponins characterization based on fragmentation rules. In total, 707 saikosaponins were characterized, including over 500 potential new compounds and previously unreported C29 aglycones. We identified 25 saikosaponins present in both authentic species but absent in adulterants as potential markers. This unprecedented comprehensive multi-origin species differentiation demonstrates the promise of MATLAB-assisted acquisition and processing to advance saponin identification and standardize the Radix Bupleuri market. [ABSTRACT FROM AUTHOR]

• Simulations of CCC separations at different scales are compared. • Exact and approximate modeling of CCC separations is considered. • Simple equations for modeling analytical and preparative separations. • Industrial CCC separations based on traditional extraction equipment. • Exact equations for modeling industrial CCC separations. Analytical, preparative and industrial scale counter-current chromatography (CCC) processes differ in the volumes of the loaded solution of components to be separated and in the design of the equipment. Preliminary mathematical modeling is necessary for selection of the optimal design and operation mode of these CCC separations. This study aims to compare simulations of CCC separations at different scales, using an exact description based on the model of equilibrium cells and a much simpler approximate solution based on the Gaussian distribution. Equations for modeling CCC separations of different scales and examples of simulation these separations are presented. It is shown that the discrepancy between the two simulations increases with an increase in the volume of the loaded solution of the components and a decrease in the number of equilibrium cells of a CCC device. In analytical and preparative separations, which are based on complex centrifugal devices, and relatively small sample volumes are injected, approximate equations can be used to simulate various options of CCC separation. In industrial-scale CCC separations, large volumes of the solution of components may be loaded, and as we have proposed previously, these separations can be based on a cascade of mixer-settler extractors. In this case, a more accurate mathematical description based on the cell model equations should be used for modeling. [ABSTRACT FROM AUTHOR]

• Blood microsampling device validated for quantification of 72 PFAS. • Microsampling requires minimal handling and method simplicity for PFAS analysis. • Microsampling allows for straightforward analyte extractions from whole blood. • Useful tool for large scale human biomonitoring studies. Microsampling allows the collection of blood samples using a method which is inexpensive, simple and minimally-invasive, without the need for specially-trained medical staff. Analysis of whole blood provides a more holistic understanding of per- and polyfluoroalkyl substances (PFAS) body burden. Capillary action microsamplers (Trajan hemaPEN®) allow the controlled collection of whole blood as dried blood spots (DBS) (four 2.74 µL ± 5 %). The quantification of 75 PFAS from DBS was evaluated by comparing five common extraction techniques. Spiked blood (5 ng/mL PFAS) was extracted by protein precipitation (centrifuged; filtered), acid-base liquid-liquid extraction, trypsin protease digestion, and weak anion exchange (WAX) solid-phase extraction with analysis by high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Filtered protein precipitation was the most effective extraction method, recovering 72 of the 75 PFAS within 70 to 130 % with method reporting limit (MRL) for PFOS of 0.17 ng/L and ranging between 0.05 ng/mL and 0.34 ng/mL for all other PFAS. The optimised method was applied to human blood samples to examine Inter- (n = 7) and intra-day (n = 5) PFAS blood levels in one individual. Sixteen PFAS were detected with an overall Σ 16 PFAS mean = 6.3 (range = 5.7–7.0) ng/mL and perfluorooctane sulfonate (branched and linear isomers, ΣPFOS) = 3.3 (2.8–3.7) ng/mL being the dominant PFAS present. To the authors knowledge, this minimally invasive self-sampling protocol is the most extensive method for PFAS in blood reported and could be a useful tool for large scale human biomonitoring studies. [ABSTRACT FROM AUTHOR]

Highlights • 1 Five kinds of hydrophobic DESs were designed and prepared for the first time. • 2 The prepared DESs showed high extraction efficiency for formaldehyde (HCHO). • 3 The DES was applied to extract and determine of HCHO in biological and gas samples. • 4 Hydrophobic DESs based VA-LLME combined with HPLC method was developed. Abstract Hydrophobic deep eutectic solvents (DESs) are a new class of green solvents, and their research and application are a brand new area. So far, only a few hydrophobic DESs have been reported as extraction solvents. In this paper, five kinds of hydrophobic DESs composed of trioctylmethylammonium chloride and hydroquinone, 4-phenylphenol or 4-cyanophenol are designed and prepared for the first time. Melting point / glass transition temperature and density are also determined for these DESs. Coupled with HPLC, these hydrophobic DESs have been used as extractants in vortex-assisted liquid-liquid microextraction for the selective enrichment and indirect determination of formaldehyde. The optimization of reaction and extraction conditions, such as pH value, reaction time and temperature, concentration of 2,4-dinitrophenylhydrazine, type and dosage of the extraction solvent, speed and time of vortex, salt addition and centrifugation time are investigated in detail. It is found that under the optimized experimental conditions, the calibration curve of this method is linear in the range of 1.0–200.0 μg L−1 with the linear correlation coefficient (r2) of 0.9994. The limit of detection (S/N = 3) and limit of quantification (S/N = 10) are 0.2 μg L−1 and 1.0 μg L−1, and the intra-day and inter-day precision (RSD, n = 5) are 1.1% and 3.5%, respectively. The interference of some common coexisting ions and neutral molecules have been also tested. The proposed method has been successfully used for the determination of formaldehyde from biological and indoor air samples. The recovery of formaldehyde is in the range from 83.1% to 104.4%, and the relative standard deviation is lower than 5.9%. Furthermore, the analytical parameters of the proposed method have been compared with other extraction and microextraction methods. [ABSTRACT FROM AUTHOR]

Highlights • A hydrophilic deep eutectic solvent (DES) was easily synthesized. • The DES was used in reversed liquid-liquid microextraction. • Vortex was used to assist the extraction from edible oil samples. • DoE was used for the method optimization. Abstract In this study, four triazine herbicides—namely, simazine, ametryn, prometryn and terbuthylazine—were separated and determined using high-performance liquid chromatography coupled with ultraviolet detector (HPLC-UVD). The deep eutectic solvent (DES) formed by tetrabutylammonium chloride ([N 4444 ]Cl, TBA) and ethylene glycol (EG) was selected as the extraction solvent of vortex-assisted reversed-phase liquid-liquid microextraction (VA-RPLLME). The application of the hydrophilic DES expands the range of choice for LLME. The experimental parameters affecting the extraction recoveries, including the amount of the DES, the sample volume and the vortex time, were investigated and optimized by the design of experiments (DoE) methodology. A quadratic model, namely central composite face-centered (CCF) design featuring 20 runs was used instead of the conventional trial and error approach. Under optimum conditions, the limits of determination (LODs) of the method were 0.60–1.50 μg L−1. The enrichment factors for the analytes ranged from 27 to 31. The extraction recoveries were in the range of 84.1–104.9%, and the intra-day, inter-day and intermediate relative standard deviations (RSDs) were less than 8.4%. Finally, the method was applied for the determination of triazine herbicides in vegetable oil samples. The obtained recoveries were in the range of 60.1–107.2% and RSDs were lower than 8.1%. In general, VA-RPLLME can be complementary to the present available methods for the determination of triazine herbicides in vegetable oil samples. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Air-assisted dispersive liquid-liquid microextraction with organic phase solidification (AA-DLLME-OPS). • AA-DLLME-OPS using menthol. • AA-DLLME-OPS coupled with HPLC-UV. • HPLC-UV determination of benzoic and sorbic acids in beverages and soy sauce. Abstract A simple and highly-available air-assisted dispersive liquid-liquid microextraction procedure with organic phase solidification (AA-DLLME-OPS) was developed as new approach for pretreatment of complex sample matrix. Menthol was investigated as novel extractant for the AA-DLLME-OPS. In this procedure, a cloudy solution of fine molten menthol droplets is formed when a mixture of molten menthol and aqueous sample is rapidly aspirated into a dispenser and injected into an extraction vial. In the AA-DLLME-OPS, air bubbles promote molten menthol dispersion into aqueous sample phase. Finally, the obtained mixture is cooled and menthol phase is solidified because of the low melting point, which facilitates collection for analysis. To demonstrate the efficiency of the suggested approach, the AA-DLLME-OPS procedure was applied for the HPLC-UV determination of benzoic and sorbic acids as proof-of-concept analytes in beverages and soy sauce samples. The procedure developed provides microextraction of benzoic and sorbic acids from samples with recovery from 93 to 105% and from 96 to 101%, respectively. Under optimal experimental conditions the linear detection ranges were found to be 0.1–150 mg L−1 for benzoic acid and 0.05–100 mg L−1 for sorbic acid with LODs calculated from a blank test, based on 3σ, 0.03 mg L−1 and 0.02 mg L−1, respectively. [ABSTRACT FROM AUTHOR]

Highlights • Magnetic ionic liquids (MILs) for in situ dispersive liquid-liquid microextraction. • MILs contain paramagnetic cations and undergo metathesis during the microextraction. • Analyte-enriched hydrophobic MIL is isolated by magnetic separation, followed by HPLC. • MILs with N-benzylimidazole and N-butylimidazole ligands exhibited best performance. • The MILs are valid for the determination of organic pollutants in aqueous samples. Abstract A new class of magnetic ionic liquid (MIL) containing paramagnetic cations has been applied for in situ dispersive liquid-liquid microextraction in the determination of both polar and non-polar pollutants, including ultraviolet filters, polycyclic aromatic hydrocarbons, alkylphenols, a plasticizer and a preservative in aqueous samples. The MILs were based on cations containing Ni(II) metal centers coordinated with four N-alkylimidazole ligands and chloride anions. The MILs were capable of undergoing in situ metathesis reaction with the bis[(trifluoromethyl)sulfonyl]imide ([NTf 2 −]) anion during the microextraction procedure, generating a water-immiscible extraction solvent containing the preconcentrated analytes. The MIL was then isolated by magnetic separation, followed by direct analysis using reversed-phase high performance liquid chromatography with diode array detection. Among all of the studied MILs, those containing the N-butylimidazole and N-benzylimidazole ligands ([Ni(C 4 IM) 4 2+]2[Cl-] and [Ni(BeIM) 4 2+]2[Cl-], respectively) exhibited the best extraction performance. The method under optimum conditions required 5 mL of sample at pH 3, 20 mg of [Ni(C 4 IM) 4 2+]2[Cl-] or 30 mg of [Ni(BeIM) 4 2+]2[Cl-], 300 μL of acetone or acetonitrile as dispersive solvent (depending on the MIL), a 1:2 M ratio of MIL to [NTf 2 −], and 3 min of vortex. The developed method achieved higher extraction efficiency compared to the conventional MIL-dispersive liquid-liquid microextraction mode, with extraction efficiencies of 46.8–88.6% and 65.4–97.0% for the [Ni(C 4 IM) 4 2+]2[Cl-] and the [Ni(BeIM) 4 2+]2[Cl-] MILs (at a spiked level of 81 μg L-1), respectively, limits of detection down to 5.2 μg L-1, and inter-day relative standard deviation lower than 16%. [ABSTRACT FROM AUTHOR]

Highlights • We developed the first SALLME for Trimethoprim with sulfonamides in water samples. • Tolerance intervals enabled calculation of SALLME design space. • Tolerance intervals based design space ensure robustness of SALLME procedure. • Perchlorate addition to extract trimethoprim at pH range suitable for sulfonamides. • Probabilistic robustness was applied to construct design space for HPLC system. Abstract Sulfonamides and trimethoprim combinations have been used extensively as antimicrobial agents for prevention and treatment of human and animal infections. Although many microextraction methods were developed for monitoring their residues in environmental water, none of these methods applied liquid-liquid microextraction for this purpose. This work presents for the first time a simultaneous Salt Assisted Liquid-Liquid Microextraction SALLME coupled with HPLC-UV for determination of trimethoprim and six common sulfonamide residues (sulfathiazole, sulfadiazine, sulfadmidine, sulfamethoxazole sulfadoxine and sulfaquinoxaline) in water samples. Co-extraction of trimethoprim with sulfonamides was achieved by the addition of perchloric acid as a chaotropic agent to the extraction medium. Quality by Design framework was applied to develop and optimize both of SALLME and HPLC steps to ensure procedure robustness and sensitivity. Tolerance interval modeling of SALLME responses was applied to construct the design space of SALLME procedure. The optimized HPLC system enabled fast, sensitive and robust separation the extracted compounds within four minutes. The method detection limits of the method were in the range of 2.15–7.64 ng.mL−1. These values were far below the guidelines recommended limits (35 and 70 ng.mL−1 for each individual sulfonamide and trimethoprim respectively). [ABSTRACT FROM AUTHOR]

Highlights • The VALLME-GC/MS method is simple and sensitive to analyse seven urinary triazoles. • The method offers selectivity to triazoles tested in addition to other interferents. • The method presented satisfactory analytical performance to exposure assessment. • The method is a promising tool to biomonitoring of exposed to triazoles. Abstract The development and validation of an innovative, simple, rapid, selective and sensitive vortex-assisted liquid-liquid microextraction-gas chromatography- mass spectrometry (VALLME-GC/MS) method to seven triazole fungicides in urine is reported. The confidence parameters were exhaustive evaluated and linearity (r > 0.99), precision (below 15%, to quality controls, and 20%, to lower limit of quantification), accuracy and robustness were adequate for the analysis of cyproconazole, epoxiconazole, metconazole, tebuconazole, triadimenol, propiconazole and triadimefon. To assess the applicability of the method, analyses were performed in volunteers exposed to triazoles in the last 30 days. The method demonstrated satisfactory analytical performance, with sufficient detectability to be applied as a potential tool to biomonitoring individuals exposed to the seven evaluated fungicides. [ABSTRACT FROM AUTHOR]

Highlights • A two-step LLE is proposed to improve non-polar analyte extraction recovery. • EMR-Lipid cartridges provide pass-through cleanup for samples. • Method is validated for multiclass multiresidue pesticides testing in edible oils. • Improved GC–MS/MS method robustness is demonstrated. Abstract This study presents the development and validation of a method for the multi-class multi-residue analysis of pesticide residues in edible oils using liquid-liquid extraction followed by EMR-Lipid (enhanced matrix removal - lipid) cartridge cleanup, and then analyzed by gas chromatography tandem mass spectrometer (GC–MS/MS). The method was optimized for analyte recovery, matrix removal, and water removal during the sample extraction, sample cleanup and sample drying steps. The extraction efficiency of lipophilic pesticides (i.e. organochlorine) from the hydrophobic oil matrix was improved using a two-step liquid-liquid extraction with a mixture of ethyl acetate and acetonitrile. EMR-Lipid cartridges provided efficient and selective cleanup of the tested oil matrices. The developed method was verified by analyzing four edible oil matrices: olive oil, corn oil, soybean oil and canola oil. The results demonstrated that the method effectively removes unwanted matrix co-extractives better than conventional PSA/C18 dispersive solid phase extraction (dSPE) cleanup, while still delivering acceptable recovery results (recoveries of 60–120%) for the majority of pesticides tested. With the established quantification method, over 95% of the pesticides obtained for 70–120% accuracy, RSD < 20%, and calibration curves from 1 to 500 (400) ng/g in oil with R2 > 0.99. [ABSTRACT FROM AUTHOR]

Highlights • Analytical procedures were automatically carried out, minimizing any errors related. • Detect nanomolar of sulfite in a few minutes with good repeatability and recovery. • Inexpensive, light (3.9 kg), simple to use, applicable to on-site analysis. • Promising analytical performance was achieved compared with its other off-line modes. Abstract Sulfite is known to be harmful to human health and associated to sulfur related environmental effects and ideally should be analyzed onsite owing to its instability. Here we describe an automated, miniaturized, and highly efficient dispersive liquid-liquid microextraction (DLLME) system that seamlessly coupled to a UV–vis spectrophotometer for the trace analysis of sulfite in natural waters. The automated DLLME system was constructed by a single syringe pump that is coupled with a multiposition valve. Nanomolar levels of sulfite could be extracted from natural water samples and injected into the hyphenated spectrophotometer for quantification. The whole analytical procedures, including chromogenic reactions, DLLME, collecting and transferring of microvolume of extracts, and spectrophotometric quantification, were automatically carried out. Key parameters that affect the performance of the method were investigated. The method allows the determination of trace levels of sulfite in the range of 15–1500 nM with a detection limit of 1.2 nM. Good reproducibility and recoveries were obtained by analyzing a series of natural water samples that were spiked with different concentration levels. The method was successfully applied to real natural water samples with satisfactory results. The proposed analytical system is light (3.9 kg), simple to use, able to be applied in the field, and sensitive enough for fresh and saline waters analysis. [ABSTRACT FROM AUTHOR]

Highlights • A RRLC-DAD method was set up and validated for 19 isoprenoids in a faecal matrix. • The method shows good analytical validation parameters in a run time of only 28 min. • 25 carotenoids isomers, 9 chlorophylls derivatives and 2 tocopherols are identified. • The method is suitable for isoprenoids bioaccessibility evaluation in human studies. Abstract An analytical method was validated for the quantitative determination of isoprenoids compounds in faecal samples, based on liquid-liquid extraction from a small aliquot (0.3-0.5 g of sample) and subsequent analysis by Rapid Resolution Liquid Chromatography (RRLC) on a C30 column. An excellent linear response was observed over the range specified for all dietary isoprenoids, as confirmed by the correlation coefficient, which ranged from 0.9977 to 0.9999. LODs ranged from 0.002 μg to 0.036 μg for lutein and α-tocopherol, respectively. Depending on the compound, LOQs ranged from 0.001 μg (lutein) to 0.120 μg (α-tocopherol). For accuracy testing, spiking of faeces samples with trans-β-apo-8′-carotenal, α-tocopherol and chlorophyll a were performed (three concentration levels). Excellent recoveries were obtained in all levels (>90%). The intra-day RSD% ranged from 0.86 to 9.78%. The inter-day RSD% was not higher than 10%, except to α-tocopherol (11.34%). In order to assess the applicability of the method faecal samples from a baby fed with different purees formulated from various vegetables were analysed during a six month period. α-carotene, β-carotene, capsanthin, lycopene, lutein, phytoene, phytofluene, violaxanthin, zeaxanthin and ζ-carotene), and their isomers were identified and quantified using this method. Besides, 2 tocopherols and 9 chlorophylls and derivatives were identified and quantified in the faecal samples analysed. This method is suitable to determine dietary isoprenoids from complex matrices such as human faeces within 28 min. [ABSTRACT FROM AUTHOR]

Highlights • Extraction of tyrosine kinase inhibitors by salting-out liquid–liquid extraction. • Analysis of tyrosine kinase inhibitors by capillary electrophoresis technique. • In-line concentration by acetonitrile stacking at high sample volume injected. Abstract Developing an easy to use, cheap and fast analytical methodology is highly demanded for clinical practices, such as therapeutic drug monitoring (TDM). The present work deals with the development of an analytical methodology for the analysis of four basic anticancer drugs, namely tyrosine kinase inhibitors (TKIs), in human plasma by combining salting-out assisted liquid–liquid extraction (SALLE) with capillary electrophoresis (CE). This SALLE-CE methodology makes a full use of the advantages of both techniques by combining extraction, on-line concentration and separation in a simple way. First, plasma samples containing TKIs are mixed with acetonitrile (ACN) in appropriate volumes to precipitate proteins. After vortexing and centrifugation, sodium chloride (NaCl) is added to the plasma-ACN mixture to induce a two phases separation. TKIs are efficiently extracted (60–100% extraction efficiency) in the upper (mostly organic) phase which is directly analyzed by capillary electrophoresis (CE) coupled to UV detection. The high content of ACN in the upper phase allows the stacking of the analytes in the capillary (on-line stacking) during analysis. For the first time thanks to this electrophoretic process, the injected sample volume can be as large as 80% of the capillary volume (till the detector window). Good linearity was obtained for each TKI in the concentration range 60–2000 ng/ml with correlation coefficient (r²) between 0.997 and 0.999. LOD and LOQ in human plasma with such large injected volume were determined from 16 to 280 ng/ml and from 62 to 900 ng/ml respectively depending on the TKI. Recoveries for the four TKIs ranged from 60 to 100%. The repeatability of the SALLE-CE methodology for the analysis of TKIs in human plasma was evaluated with injected sample volume equal to 80% of the capillary volume till detector window. Relative standard deviations (RSDs) of less than 1.24 and 2.84% on migration times and corrected peak areas respectively were obtained at the LOQ. The sensitivity was enhanced by 61 to 265 folds confirming the applicability of the proposed methodology for the assay of TKIs in patients' plasma. [ABSTRACT FROM AUTHOR]

Highlights • Liquid anion exchangers were used in DLLME for the extraction of inorganic anions. • There was no need to perform a chemical reaction before the extraction. • So, the method was simple and environmentally friendly. • Also, the multicomponent analysis was possible by the method. • The DLLME method followed by HPLC-UV was applied for real sample analysis. Abstract For the first time, the possibility of the use of liquid anion exchangers in dispersive liquid–liquid microextraction for the direct extraction of some inorganic anions (nitrite, nitrate, and iodide) was evaluated. In this technique, chloroform containing a liquid anion exchanger (trioctylamine) was used as extractant. The mixture of the extractant and disperser solvent (acetonitrile) was injected into the acidic sample solution. The protonated trioctylamine formed a water-insoluble salt with the inorganic anions (analytes). After the phase separation and stripping of the analytes from the extractant, the analytes were determined by liquid chromatography with UV detection. Various parameters affecting the extraction efficiency were investigated. Under the optimum conditions, broad linear dynamic ranges, with determination coefficients (r2) higher than 0.998, and enrichment factors between 94 and 244 were obtained. The limits of detection and quantification were in the range of 0.1–0.5 and 0.4–1.7 μg L−1, respectively. Also, the values of intra- and inter-day relative standard deviations were 3.5–5.8% and 5.5–7.8%, respectively. Various real water samples including sea, tap, river, spring and mineral water were analyzed by the method. The method was sensitive, simple, inexpensive and capable of the simultaneous extraction and determination of the selected inorganic anions. [ABSTRACT FROM AUTHOR]

Highlights • A magnetic ionic liquid-based dispersive liquid-liquid microextraction is presented. • Quartz silica was used as a solid support for the magnetic ionic liquid. • A pH-modulated approach was employed to extract sulfonamides and triazines. • Sulfonamides and triazines were determined in environmental water using HPLC-DAD. Abstract In this study, an enhanced variant of magnetic ionic liquid (MIL)-based dispersive liquid-liquid microextraction is put forward. The procedure combines a water insoluble solid support and the [P 66614 +][Dy(III)(hfacac) 4 −] MIL, in a one-pot, pH-modulated procedure for microextraction of triazines (TZs) and sulfonamides (SAs). The solid supporting material was mixed with the MIL to overcome difficulties concerning the weighing of MIL and to control the uniform dispersion of the MIL, rendering the whole extraction procedure more reproducible. The pH-modulation during extraction step makes possible the one-pot extraction of SAs and TZs, from a single sample, in 15 min. Overall, the new analytical method developed enjoys the benefits of sensitivity (limits of quantification: 0.034–0.091 μg L-1) and precision (relative standard deviation: 5.2–8.1%), while good recoveries (i.e., 89–101%) were achieved from lake water and effluent from a municipal wastewater treatment plant. Owing to all of the above, the new procedure can be used to determine the concentrations of SAs and TZs at levels below the maximum residue limits. [ABSTRACT FROM AUTHOR]

As a well-known extraction procedure, electromembrane extraction (EME) was combined with electro-assisted liquid-liquid microextraction (EA-LLME) in the present work, which resulted in a promising method. This hyphenated sample preparation method, named EME-EA-LLME, was followed by GC for the determination of two model analytes (clomipramine and imipramine). The effective parameters of both EME and EA-LLME (such as organic solvent, pH of acceptor and sample solutions, voltage and extraction time) were optimized. The proposed EME-EA-LLME procedure demonstrated good linearity with coefficients of determination, R 2 ≥ 0.998 over the concentration range of 0.5–750 ng/mL. Limit of detection for both analytes was 0.15 ng/mL. The corresponding repeatability ranged from 6.9 to 12.2% (n = 3). The high enrichment factors were obtained as 770.3 and 561.4 for imipramine and clomipramine, respectively. The advantages of this tandem sample preparation method were low detection limits, simplicity, low cost, and short analysis time (<10 min). Finally, the optimized method was used to extract and determine the analytes in urine and wastewater samples. Overall, the results revealed that the developed EME-EA-LLME procedure had better extraction efficiency in comparison with EME and EA-LLME alone. [ABSTRACT FROM AUTHOR]

A simple and rapid method for the extraction of organochlorine compounds (OCs) including poly-chlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in fish liver using ultrasound assisted dispersive liquid–liquid microextraction based on the solidification of floating organic droplet (US-DLLME-SFO) was developed. For reducing the complexity of the matrix, the sample was pre-treated prior to microextraction. Factors affecting US-DLLME-SFO were optimized by using statistical design of experiment (DoE). The analysis was carried out by Gas Chromatography (GC) equipped with micro electron capture detector (μ-ECD). The optimized parameters were 4.8 min of ultrasound, 3.0 mL of Milli-Q and 24 μL of 1-undecanol as an extraction solvent as determined by DoE. US-DLLME-SFO was validated in terms of limit of detection, limit of quantification, dynamic linearity range, coefficient of determination (linearity) and extraction recovery in fish liver for OCs, and the respective values were (1.06-3.84 ng g −1 ), (3.50-12.67 ng g −1 ), (1.0–500 ng g −1 ), (R 2  = 0.994-0.999), (88.5-108.4%). Interday and intraday precisions were evaluated as relative standard deviation (% RSD) and the values were ≤10%. [ABSTRACT FROM AUTHOR]

Ionic liquid-based aqueous biphasic systems (IL-ABS) formed by ILs composed of ions of low toxicity, choline ([Chol] + ) coupled with saccharinate ([Sac] − ) and acesulfamate ([Ace] − ), and inorganic salts with distinct water-structuring properties were employed for simultaneous extraction and concentration of acetylcholinesterase (AChE) inhibitors – galantamine ( gal ), N -desmethyl galantamine ( des ) and ungiminorine ( ung ). Comprehensive experiments aimed to assess the influence of salt and IL type and concentration, as well as the pH and temperature on the phase-forming ability and distribution of the target alkaloids between the two phases formed reveled that the IL anion and pH are the most important factors. At the optimal conditions found a quantitative recovery into the IL-rich phase of gal , des and ung was achieved in a single extractive step. These results were further used as a platform for the development of a simple and safer sample pretreatment method for analysis of the three analytes, followed by RP-HPLC/UV detection. The method showed satisfactory analytical performance, the latter allowing quantitative determination of these AChE inhibitors in pharmaceutical dosage form and in human urine. [ABSTRACT FROM AUTHOR]

In this work, a novel, fast, and sensitive method was developed for perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS) and PFOS precursor’s determination in seawater. The proposed method consists in a vortex-assisted liquid-liquid microextraction (VALLME) combined with liquid chromatography (LC) and LTQ-Orbitrap high resolution mass spectrometry (LTQ-Orbitrap HRMS) determination. Several parameters affecting both the HPLC-LTQ Orbitrap HRMS determination and the VALLME were studied, with special attention to blank contamination problem. The use of LTQ-Orbitrap-HRMS in full mode, quantifying the target analytes using the exact mass, provides a very powerful detection in terms of sensitivity and specificity maintaining all the information provided by the full mass spectra, allowing, also, the identification of non-target substances. The use of matrix-matched calibration, together with labelled surrogate standards, minimize matrix effects and compensate potential recovery losses, resulting in recoveries between 95 and 105%, with excellent sensitivity (quantitation limit between 0.7 and 6 ng L −1 ) and precision (4–10%). The proposed method requires only 35 mL of sample and 100 μL of extracting solvent, is fast and avoids the use of other solvents to obtain the dispersive cloudy solution, simplifying the procedure and improving the existing procedures for the determination of per- and polyfluoroalkyl substances (PFASs) in seawater in terms of green analytical chemistry. The method was successfully validated by participating in a proficiency test assay provided by the National Measurement Institute of the Australian Government for the determination of PFOA, total PFOS and linear PFOS in waters. A revision of the state of the art in the last twelve years of methods for the analysis of PFASs in seawater and other types of water was performed, and a critical comparison between the developed method and the previously published was included. Finally, the method was applied to the analysis of samples from Ría de Vigo, a sensitive and semiconfined coastal area located in the northwest of Spain. PFOS, N-methyl perfluorooctanesulfonamide ( n -MeFOSA) and N -ethyl perfluorooctanesulfonamide ( n -EtFOSA) were detected in samples at levels lower than the maximum allowable concentration (MAC) established by Directive 2013/39/EU, but above the annual average (AA) levels. [ABSTRACT FROM AUTHOR]

A novel and efficient approach to optimization of extraction step prior the chromatographic determination of nine chlorinated phenols is described. It is based on the combination of design of experiments and multicriteria decision analysis. Such an approach is used to optimize dispersive liquid-liquid microextraction procedure for the determination of 9 chlorophenols in water samples. Three parameters are optimized – sample volume, volume of disperser solvent and extraction solvent. Combination of the technique for order of preference by similarity to ideal solution with central composite design allows to perform multi-analyte procedure optimization. It gives information about the efficiency of the system for every experimental plan point in terms of closeness to ideal solution. The optimal conditions for extraction of chlorophenols are 76 μL of extraction solvent, 0.6 mL of dispersive solvent and 6.7 mL of water sample. The presented approach has the potential to be applied in variety of optimization systems. [ABSTRACT FROM AUTHOR]

A fast and effective method using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach which includes partitioned liquid-liquid extraction (PLLE) and dispersive solid phase extraction (dSPE) clean-up step for the determination of seven 3-monochloropropane-1,2-diol (3-MCPD) fatty acid diesters in vegetable oils is developed and validated according to the Food and Drug Administration (FDA) guidelines. Due to the complexity of the matrices, combination of silica based sorbents (Silica Strong Anion Exchange (Si-SAX), Supel™ QuE Z-Sep+ (Z-Sep+) and Primary Secondary Amine (PSA) were tested for lipid removal. The effect of several experimental factors on the efficiency of the extraction procedure was studied by a screening design 3 4 2 2 //16 and a response surface Doehlert design. The separation and determination was carried out by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). The method provided suitable linearity (r 2  > 0.9960), precision (relative standard deviation (RSD) lower than 10%) and accuracy, in terms of recovery. The limits of detection (LOD) and limits of quantification (LOQ) ranged from 10 to 20 μg kg −1 and from 25 to 50 μg kg −1 , respectively. The recoveries at three spiking levels of 100, 250, and 500 μg kg −1 were over the range of 71.4–122.9% with RSD lower than 13%. The method was successfully applied in edible oils and fatty food samples. The results provide valuable information to assess the risk of exposure to these foodborne contaminants. [ABSTRACT FROM AUTHOR]

In the present study, a highly selective fluorous affinity-based dispersive liquid–liquid microextraction (DLLME) technique was developed for the extraction and analysis of per- and polyfluoroalkyl substances (PFASs) followed by high performance liquid chromatography tandem–mass spectrometry. Perfluoro- tert -butanol with multiple C-F bonds was chosen as the extraction solvent, which was injected into the aqueous samples with a dispersive solvent (acetonitrile) in a 120:800 (μL, v/v) mixture for PFASs enrichment. The fluorous affinity-based extraction mechanism was confirmed by the significantly higher extraction recoveries for PFASs containing multiple fluorine atoms than those for compounds with fewer or no fluorine atoms. The extraction recoveries of medium and long-chain PFASs (CF 2  > 5) exceeded 70%, except perfluoroheptanoic acid, while those of short-chain PFASs were lower than 50%, implying that the proposed DLLME may not be suitable for their extraction due to weak fluorous affinity. This highly fluoroselective DLLME technique can greatly decrease the matrix effect that occurs in mass spectrometry detection when applied to the analysis of urine samples. Under the optimum conditions, the relative recoveries of PFASs with CF 2  > 5 ranged from 80.6-121.4% for tap water, river water and urine samples spiked with concentrations of 10, 50 and 100 ng/L. The method limits of quantification for PFASs in water and urine samples were in the range of 0.6–8.7 ng/L. Furthermore, comparable concentrations of PFASs were obtained via DLLME and solid-phase extraction, confirming that the developed DLLME technique is a promising method for the extraction of PFASs in real samples. [ABSTRACT FROM AUTHOR]