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This paper proposes a simple ion chromatographic approach to determine trace amounts of perchlorate in river water samples. Determination of the trace perchlorate by ion chromatography typically faces two challenges: interference by matrix ions such as chloride, nitrate, and sulfate in the samples and insufficient detection sensitivity. In the present study, online pretreatment of the samples with an OnGuard II Ba/Ag/H disposable sample pretreatment cartridge prevented the sulfate peak tailing from overlapping with the perchlorate peak on the chromatogram. In addition, the matrix removal enabled as large as 10 mL of sample to be loaded into a high exchange capacity anion concentrator, significantly improving perchlorate's detection sensitivity. The proposed approach achieved a detection limit (S/N = 3) of 0.046 µg L-1 without using a costly mass spectrometer and successfully determined sub µg L-1 levels of perchlorate in river water.

In order to monitor the risk of pesticide pollutants in drinking water, an analytical method based on online-solid phase extraction coupled with ultra performance liquid chromatography-triple quadrupole mass spectrometry (online-SPE-UPLC-MS/MS) was established for the simultaneous rapid screening and determination of 107 pesticides and metabolites (organophosphorus, organic nitrogen, organic heterocycle, carbamate, amide, benzoyl urea, neonicotinoid, etc.) in raw water and drinking water. Different injection volumes (5, 10, and 15 mL) were compared. The detection response increased with an increase in the injection volume, but the matrix effect also became more pronounced. Under the premise of ensuring the sensitivity of the method and meeting the detection requirements, the injection volume was selected as 5 mL. Accordingly, the samples were filtered through a 0.22-μm hydrophilic polytetrafluoroethylene filter, and then, 5 mL samples were injected into the online-SPE system by the automatic sampler. After adsorption on an X Bridge C

A method was developed for the determination of 10 organic acids in liquor, yellow rice wine, and dry red wine by ion chromatography-triple quadrupole mass spectrometry (IC-MS/MS). First, the liquor samples were diluted with deionized water, degassed with nitrogen, and analyzed by IC-MS/MS. Then, the yellow rice wine and dry red wine samples were purified with different solid-phase extraction cartridges. Finally, the GCB solid-phase extraction cartridge was selected for purification, diluted with deionized water, and analyzed by IC-MS/MS. The samples were separated using a Dionex IonPac AS11-HC anion analysis column with high capacity and strong hydrophilicity, with an KOH aqueous solution as the eluent, which was produced by an automatic generator for gradient elution. After being suppressed using a suppressor, the eluent was injected directly into the electrospray ionization tandem mass spectrometry (ESI-MS/MS), ionized in negative ion mode, detected in multiple reaction monitoring (MRM) mode, and quantified using an external standard method. Oxalic acid, fumaric acid, maleic acid, malic acid, tartaric acid, citric acid, quinic acid, and aconitic acid showed good linear relationships in the range of 0.05-2 mg/L. Succinic acid and lactic acid showed good linearities in the range of 0.05-5 mg/L and 0.05-10 mg/L, respectively. The correlation coefficients (

The main methods currently used to detect illegally added chemicals in cosmetics include thin-layer chromatography, high performance liquid chromatography (HPLC), gas chromatography (GC), and liquid chromatography-mass spectrometry (LC-MS). Compared with other analytical techniques, these methods have the advantages of high sensitivity, specificity, and accuracy, all of which are required in practical detection work. However, they also present a number of limitations, such as long analysis times and requirements for skilled operators and strictly controlled laboratory environments. Supervision, a growing trend in market surveillance, requires rapid and effective methods to screen illegally added chemicals. The suspected samples are sealed for some time and then sent to the laboratory for further testing. Ion mobility spectrometry (IMS) is a new type of trace gas separation technology that was developed in recent years. The principle behind IMS is the separation and characterization of chemical species based on differences in the migration speed of their gas-phase ions under an electric field. As this technology has the advantages of miniaturization, easy operation, and quick responses, it is widely used in food and drug quality testing, as well as other related fields. However, it is rarely used in cosmetic detection, likely because the cosmetics matrix is highly complex, which can interfere with ion determination. Thus, optimizing the pretreatment process of cosmetics for IMS is important. In this work, solid-phase extraction (SPE) is combined with IMS to establish a method for the rapid screening of 14 antibacterial drugs in anti-acne cosmetics. The IMS detection parameters, sample extraction conditions, and SPE clean-up conditions (SPE column, type of leachate, type and volume of eluent) were studied and optimized in detail. The sample was extracted with 80%(v/v) acetonitrile aqueous solution (containing 0.2% (mass fraction) trichloroacetic acid), loaded onto an activated Oasis

This research aimed to quantify the speciation of chromium in different industrial effluent samples of Hyderabad and Jamshoro, Pakistan. The hexavalent chromium (Cr(VI)) was determined by microsample injection system flame atomic absorption spectroscopy (MIS-FAAS). The total chromium was measured by MIS-FAAS after the oxidation of trivalent chromium (Cr(III)) to hexavalent chromium (Cr(VI)) by Ce(SO4)2 in an acidic medium (0.07 M H2SO4). The content of Cr(III) was measured by the difference method (total chromium – hexavalent chromium). In the effluent samples of textile and fabrics industries, the total Cr was observed 400 to 1600 times higher than the US-EPA and WHO regulatory limit (0.10 mg/L) in the industrial discharge. In the effluent of food and plastic industries, the Cr(VI) was found to be high as compared to the Cr(III), and the Cr(III) was observed high in the effluent samples of chemical as well as textile and fabrics industries. The Cr(VI) was higher than the US-EPA and WHO regulatory limit (0.05 mg/L) in the effluent samples of all selected industries, but the Cr(III) was within the US-EPA and WHO regulatory limit (170 mg/L) in the industrial discharges.

The eicosanoid metabolic pathway is responsible for mediating the production of various inflammatory factors that are closely related to the development and resolution of inflammation. In biological matrices, the major quantifying obstacles were shown to be the oxidation and low quantities of eicosanoids and their metabolites. This study aimed to develop a reliable, sensitive ultrahigh-performance liquid chromatography coupled to a tandem mass spectrometry (UPLC–MS/MS) method to quantify eicosanoids in human serum. Solid-phase extraction (SPE) was used for sample preparation. The approach employed continuous ionization polarity switching. The target eicosanoids showed good linearity over the investigated concentration range (r2 > 0.99). The recovery rates were over 64.5%, and the matrix effects ranged from 73.0 to 128.0%. The limits of quantification were 0.048 ~ 0.44 ng/mL. For the broad concentration range, the CV % for accuracy and precision were less than ± 20%. We successfully applied this method to rapidly analyse 74 serum samples from severe influenza pneumonia, severe bacterial pneumonia and healthy individuals. Eicosanoid-related metabolite concentrations were quantified within a range similar to those of previously published articles. Compared to healthy individuals, our application found that 20-HETE, 14,15-EET and 11,12-EET were upregulated in severe influenza pneumonia patients, while LTB4 was downregulated. 8-HETE and 5-HETE were upregulated in severe bacterial pneumonia patients, while LTE4 was downregulated. This approach provides a means for monitoring the low quantities of eicosanoids in biological matrices, and our finding that different characteristic metabolite profiles may help discriminate the induction of severe pneumonia patients.

In this study, magnetic pomelo peel-derived biochar composite was fabricated and applied as a low-cost adsorbent for the simultaneous extraction of morphine-like opioids named morphine, codeine, and 6-monoacetylmorphine from wastewaters, prior to their determination via liquid chromatography-mass spectrometry. A total of four biochar products were synthesized under different pyrolytic temperatures of 400, 500, 600, and 700°C, respectively, and the 400°C biochar was found to have the greatest extraction ability, with enrichment factors of 34, 58, and 61 for the three drugs. The primary adsorption mechanism includes π-π interaction and H-bonding. Parameters affecting the extraction of opioids were optimized. Under optimum conditions (such as pH = 7; adsorbent amount = 15 mg; sample volume = 20 ml; eluent solvent, 200 µl of methanol), the method was proved to be linear in the range of 0.05-10.0 µg/L, with coefficients of determination greater than 0.99, and the limits of detection were 0.006-0.010 µg/L. In-batch and inter-batch precisions were 1.8%-6.5% and 4.8%-10.6%, respectively. The method was successfully applied to the determination of the target opioids in the samples of influent and effluent wastewater. The developed method by using magnetic pomelo peel-derived biochar could potentially be applied for the effective estimation of illicit drug consumption.

In this study, an acid-treated-activated carbon was prepared from chestnut oak shell carbonization followed by modification with hydrochloric acid/nitric acid and then used as a new sorbent for headspace needle-trap extraction of chlorophenol compounds from aqueous solutions. Different techniques, including scanning electron microscopy, nitrogen adsorption-desorption analysis, and Fourier transform-infrared spectroscopy were used for the characterization of the sorbents. The effects of some experimental parameters, including the temperature, pH, sorbent amount, and time of extraction were optimized. The developed method is fast and sensitive, providing low and sub ng/L detection limits. The limits of detection and quantification were in the range of 0.75-5 and 5-15 ng/ml, respectively, and the equilibrium time was 20 min. Wide linearity in the range of 15-2000 ng/L with R

A novel simple and functional colorimetric methodology for on-site environmental water analysis was proposed. This method combines coloration of the analyte and extraction of the colored species on dispersed particulates during their sedimentation in the same container. The whole analysis can be performed within 15 min by comprising the addition of 1 mL of sample solution into a 1.5-mL microtube containing the powders of coloring reagents and the sedimentable fine particulates as an adsorbent. The analyte is determined by comparing the sediment color with the standard color by visual inspection or the color information of the photo image. The potential of this methodology was demonstrated through developing colorimetry for Fe

Oxysterols play a key role in many (patho)physiological processes and they are potential biomarkers for oxidative stress in several diseases. Here we developed a rapid gas chromatographic-mass spectrometry-based method for the separation and quantification of 11 biologically relevant oxysterols bearing hydroxy, epoxy, and dihydroxy groups. Efficient chromatographic separation (resolution ≥ 1.9) was achieved using a medium polarity 35%-diphenyl/65%-dimethyl polysiloxane stationary phase material (30 m × 0.25 mm inner diameter and 0.25 μm film thickness). Based on thorough analysis of the fragmentation during electron ionization we developed a strategy to deduce structural information of the oxysterols. Optimized sample preparation includes (i) extraction with a mixture of n-hexane/iso-propanol, (ii) removal of cholesterol by solid phase extraction with unmodified silica, and (iii) trimethylsilylation. The method was successfully applied on the analysis of brain samples, showing consistent results with previous studies and a good intra- and interday precision of ≤20%. Finally, we used the method for the investigation of oxysterol formation during oxidative stress in HepG2 cells. Incubation with tert-butyl hydroperoxide led to a massive increase in free radical formed oxysterols (7-keto-chol 7β-OH-chol 7α-OH-chol), while 24 h incubation with the glutathione peroxidase 4 inhibitor RSL3 showed no increase in oxidative stress based on the oxysterol pattern. Overall, the new method described here enables the robust analysis of a biologically meaningful pattern of oxysterols with high sensitivity and precision allowing us to gain new insights in the biological formation and role of oxysterols.

Mass spectrometry-based immunopeptidomics enables the comprehensive identification of major histocompatibility complex (MHC) peptides from a cell culture as well as from tissue or tumor samples and is applied for the identification of tumor-specific and viral T-cell epitopes. Although mass spectrometry is generally considered an "unbiased" method for MHC peptide identification, the physicochemical properties of MHC peptides can greatly influence their detectability. Here, we demonstrate that highly hydrophobic peptides are lost during sample preparation when C18 solid-phase extraction (SPE) is used for separating MHC peptides from proteins. To overcome this limitation, we established an optimized protocol involving restricted access material (RAM). Compared to C18-SPE, RAM-SPE improved the overall MHC peptide recovery and extended the landscape of mass spectrometry-detectable MHC peptides toward more hydrophobic peptides.

In terms of the structure of polar pollutants, the design and development of new materials that can interact with target analytes is vital for effective extraction. Diquat is a broad-spectrum herbicide with strong toxicity. It is sprayed during the growing process of vegetables because of its high efficiency and low cost. Furthermore, diquat is a polar and basic cationic organic compound. Therefore, it is necessary to develop adsorbents that can form strong interaction with diquat to extract it from complex vegetable samples. In this study, sulfonic acid-functionalized ionic liquid, 1-vinyl-3-propyl(3'-sulfonate) imidazolium chloride ([VPImi-SO

Pesticides are used in the agricultural production process to ensure the yield and quality of agricultural products. However, in recent years, environmental pollution issues caused by pesticide residues have sparked widespread concern in society. It is important to develop convenient and efficient approaches to detect and monitor pesticide residues. In this study, targeting benzoylurea insecticides (BUs), polyamidoamine dendrimer-functionalized silica nanocomposite with polydopamine coating (SiO

In this study, a covalent organic framework (COF)-TpBD-supported melamine sponge (MS) was fabricated through a one-step hydrothermal method. The obtained monolithic column was then applied in in-syringe solid-phase extraction (IS-SPE) for the separation of three volatile ingredients from serum samples. Given credit for the superior adsorption capacity of the COF and the homogeneous microporous property of MS, the developed column exhibited satisfactory separation of the targets. And the dominating adsorption mechanism was the hydrophobic interaction forces between TpBD and targets and the high mass transfer efficiency provided by the large pore structure of MS. The results of dynamic adsorption showed that the MS@TpBD column displayed much better adsorption performance than blank MS and TpBD. And it has featured great reusability up to 5 cycles and obtained satisfied recovery values (87.9 ~ 110.3%) in serum samples. As a result of sample clean-up, this column offers low limit of detections (LODs) down to 0.014, 0.010, and 0.020 μg/mL, respectively. In summary, we believe that this convenient separation column has prominent application promise in the fields of separating activity ingredients in biological samples.

Solid phase extraction combined with ultra-performance liquid chromatography-tandem mass spectrometry was developed for the simultaneous determination of 31 endocrine-disrupting chemicals in fish plasma. The strong anion exchange/primary-secondary amine cartridge and the mixed cation exchange cartridge were used in tandem instead of using a single mixed cation exchange cartridge for sample purification. Suitable eluents were selected for each of the two cartridges: 4.5% ammonia/acetonitrile solution for cartridges in tandem and acetone:n-hexane (V:V = 3:7) for the strong anion exchange/primary-secondary amine cartridge alone. With this optimized Solid phase extraction method, the recoveries of 31 endocrine disrupting chemicals were between 43.0% and 131.3%, the method detection limits were 0.45 to 1.35 ng/ml, and the limits of quantitation were 1.50-4.50 ng/ml. The innovative pretreatment method that connects two cartridges in tandem is well positioned to mitigate the matrix effects of fish plasma, thereby improving the accuracy of multiclass endocrine-disrupting chemicals determination. The significance of this method is to facilitate the application of the fish plasma model for the environmental risk assessment of endocrine-disrupting chemicals.

In 2017, the United States Department of Health and Human Services declared the widespread misuse and abuse of prescription and illicit opioids an epidemic. However, this epidemic dates back to the 1990s when opioids were extensively prescribed for pain management. Currently, opioids are still recommended for pain management, and given their abuse potential, rapid screening is imperative for patient treatment. Of particular importance is assessing pain management patient compliance, where evaluating drug use is crucial for preventing opioid abuse and potential overdoses. In this work, we utilized drift tube ion mobility spectrometry coupled with mass spectrometry (DTIMS-MS) to develop a rapid screening method for 33 target opioids and opioid urinary metabolites. Collision cross section values were determined for all target molecules using a flow-injection DTIMS-MS method, and clear differentiation of 27 out of the 33 opioids without prior chromatographic separation was observed when utilizing a high resolution demultiplexing screening approach. An automated solid phase extraction (SPE) platform was then coupled to DTIMS-MS for 10 s sample-to-sample analyses. This SPE-IMS-MS approach enabled the rapid screening of urine samples for opioids and presents a major improvement in sample throughput compared to traditional chromatographic analyses coupled with MS, which routinely take several minutes per sample. Overall, this vast reduction in analysis time facilitates a faster turn-around for patient samples, providing great benefits to clinical applications.

Zearalenone has attracted worldwide attention due to its toxic properties and threat to public health. A rapid determination method for zearalenone and its derivatives by hydrophilic covalent organic frameworks coated steel sheet (HCOFCS) combined with ambient mass spectrometry (AMS) was developed. The HCOFCS behaved as both a tip for solid-phase microextraction and a solid substrate for electrospray ionization mass spectrometry (ESI-MS). To evaluate the HCOFCS-ESI-MS method, five zearalenone and its derivatives in milk samples were determined, including zearalenone (ZEA), α-zearalenol (α-ZEL), β-zearalenol (β-ZEL), α-zearalanol (α-ZAL), and β-zearalanol (β-ZAL). After the extraction procedure, the HCOFCS was directly added with a high voltage for ESI-MS, and the analysis could be completed within 1 min. The developed method showed good linearity in the range 0.1-100 μg/L with a coefficient of determination (

A simple pretreatment method based on the combination of microwave-assisted extraction and dispersive micro solid phase extraction has been developed for the extraction of eprinomectin, doramectin, ivermectin, and abamectin from cow meat, liver, and kidney samples. The extracted drugs were determined using high-performance liquid chromatography equipped with a diode array detector. In this method, the solid samples were mixed with deionized water and organic solvent mixture, and the resulting mixtures were exposed to microwave irradiations to accelerate the analytes' extraction from the samples into the solution. Then, the supernatant was taken and mixed with a mixture of three sorbents optimized by a simplex centroid design. After vortexing and centrifuging, the sorbent particles were isolated and the adsorbed analytes onto the sorbent surface eluted with a natural deep eutectic solvent for more concentration. After centrifuging, the supernatant was taken and injected into the separation system. Acceptable repeatability (relative standard deviations ≤7.0%), high extraction recoveries (72%-86%) and enrichment factors (216-258), and low limits of detection and quantification (0.06-0.10 and 0.19-0.32 ng/g, respectively) were acquired. The method was successfully applied for the assessment of the analytes in the mentioned samples and ivermectin was found in three samples.

Considering the urgent need for the analysis of trace-level pollutants in water samples, the pre-concentration of micropollutants in water samples has been the focus of extensive research. Among current pretreatment methods, the solid phase extraction (SPE) technique has received enormous attention because of its low cost, ease of operation and high efficiency. In this work, a new adsorbent (Fe3O4@Au@DTC NPs) was acquired through modification of Fe3O4 nanoparticles (NPs) with gold (Au) and dithiocarbamate (DTC). To investigate their application ability, the adsorbent were utilized as an SPE adsorbent to enrich polycyclic aromatic hydrocarbons in water (PAHs, fluoranthene, pyrene, benzo anthracene, benzo fluoranthene, benzo pyrene). The obtained Fe3O4@Au@DTC NPs were confirmed by transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), and UV-Vis spectrum. Under optimal conditions, the calibration curves were obtained in the range of 10–500 ng L−1, while the limit of detection (LOD) ranged in 1.17–2.31 ng L−1. Furthermore, 50 mg of Fe3O4@Au@DTC NPs could extract trace PAHs from 500 mL real water samples into 1 mL eluent, and the spiked recoveries of five PAHs in river water and tap water reached 72–106% with relative standard deviations varying between 3.3–5.18%. Through the conversion of amines into DTC, we acquire desiring group modified Fe3O4 NPs, which showed great prospects in magnetic solid-phase extraction sphere and environmental field.

Polycyclic aromatic hydrocarbons and polychlorinated biphenyls are commonly categorized as persistent organic pollutants. In order to analyze these pollutants, customized stationary phases are increasingly being developed and synthesized for solid-phase extraction. In this work, we tested a new solventless solid-phase extraction approach based on the use of a Magic Chemisorber® (Frontier Lab) which consists of a bead-covered polydimethylsiloxane stationary phase with a thickness of 500 µm. These devices are directly immersed into aqueous samples and then introduced into a pyrolysis–gas chromatography-mass spectrometry system equipped with a cryofocusing system for the thermal desorption and analysis of the adsorbed species. Our new method performs better than the most recent solid-phase extraction devices, with limits of detection lower than 2.7 ng/L and limits of quantification lower than 9.0 ng/L. The method was tested on standard compounds and on an environmental sample, showing the potential to characterize other chemical species besides the persistent organic pollutants, such as phthalate plasticizers and antioxidants.

Cell membrane ligand-affinity assay is a useful tool for screening the active compounds from natural products. However, in traditional cell membrane ligand-affinity assays, natural products need to be refluxed, before being analyzed. This process consumes considerable time and energy and cannot be used for screening natural products that contain thermally unstable compounds. Therefore, an efficient analytical method is required. In this study, chitosan-based matrix solid-phase dispersion extraction was combined with cell membrane magnetic bead ligand-affinity assay to form a novel method for identifying the active compounds in Fructus Cnidii such as osthole and imperatorin. When compared with traditional cell membrane ligand-affinity assays, this assay requires less energy, extraction time (7 min), solvent volume (1.2 mL), and fewer natural products (40 mg). This indicates that the chitosan-based matrix solid-phase dispersion extraction assisted cell membrane magnetic beads ligand-affinity assay is an alternative analytical method for studying natural products.

Pharmaceuticals (PhACs) are an important group of emerging contaminants that are released continuously in the environment from wastewater treatments plants (WWTPs). They can produce biological effects even though at very low concentrations. Conventional WWTPs are not able to remove or degrade completely emerging pollutants resulting in the presence of PhACs in sewage sludge after wastewater treatment. PhACs are found in sludge at low ppb-ppt levels, and their analysis and detection is a difficult task due to the complexity of sewage sludge matrices. Hydrothermal carbonization is currently being proposed as a suitable conversion technology for sewage sludge management to recover valuable products and to be used for soil amendment. In this work, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based methodology with a dispersive solid-phase extraction (d-SPE) clean-up followed by ultra-high-performance liquid chromatography coupled with high-resolution linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ/Orbitrap MS), operated in positive ionization mode, was adopted to investigate 33 multiclass pharmaceuticals in sewage sludge and in hydrochar produced after hydrothermal carbonization. The analytical method was first optimized studying various extraction parameters and finally validated in terms of linearity, recovery, intra and inter-day precisions, expanded uncertainty (%U)/Horrat ratio at three spiking levels, matrix-effects (ME), process efficiency (PE), and limits of detection and quantification. The developed methodology fulfilled all analytical requirements and was finally applied to sludge samples from the WWTP of Ioannina city where a group of antibiotics was detected at concentrations up to 15 ng g

The composition of the traditional Chinese medicine compound preparation is complex, while the content of each active ingredient is extremely low, which brings difficulties to the plasma concentration detection. In this study, the magnetic covalent-organic frameworks were synthesized by a simple one-step Schiff base reaction and applied for the specific extraction of trace angoroside C in rat plasma prior to ultra-high-performance liquid chromatography-tandem mass spectrometry detection. The synthesized magnetic covalent-organic frameworks have high magnetic responsiveness (35.67 emu·g

This study aimed to establish a method for the rapid determination of trace estrogens in honey samples by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) using imine-linked porous covalent organic framework material (IL-COF-1) as the adsorbent for solid-phase extraction (SPE). Estradiol (E

Rice is a major dietary staple in many communities owing to its high nutritional value and characteristic aroma. Oryzanol, a mixture of ferulic acid esters of triterpene alcohols and phytosterols, is a major group of phytochemicals found in rice. 24-Methylenecycloartanyl ferulate (24MCA-FA), cycloartenyl ferulate (CA-FA), and campestanyl ferulate (Camp-FA) have been identified as the primary components of oryzanol. At present, for the quantification of oryzanol in rice and rice products, UV spectroscopy or high performance liquid chromatography (HPLC) is widely employed. However, these methods cannot differentiate individual oryzanols, resulting in higher measured values. To extract oryzanol, methods including liquid-liquid extraction, acidulation extraction, and direct solvent extraction have been typically employed, as they do not require specific extraction instrumentation. However, there has been no systematic study on the direct solvent extraction and purification conditions of oryzanol in rice. In this study, a rapid and accurate analytical method based on HPLC-MS/MS and mixed-mode anion exchange (MAX) solid-phase extraction was established to determine the content of three oryzanols (24MCA-FA, CA-FA, and Camp-FA) in rice. The MS parameters, such as the collision energy of three ion pairs of each oryzanol, were optimized. Further, the chromatographic separation conditions and response intensities of the oryzanols in different mobile phases were compared. The effects of different pretreatment conditions on the extraction efficiency of the three oryzanols in rice samples and different purification conditions on their recovery were investigated. Combined with the external standard method, the three oryzanols in rice were successfully quantified. The results showed that the baseline separation and highest response for the three oryzanols were achieved using the Agilent Eclipse XDB-C8 chromatographic column (150 mm×2.1 mm, 3.5 μm) when methanol∶ acetonitrile in a 1∶1 ratio (v/v) and an aqueous solution of 5 mmol/L ammonium acetate were used as the mobile phases for gradient elution. The extraction rate of the three oryzanols was highest when using 2.5 g of the sample, adding 20 mL of methanol, soaking for 12 h, ultrasonicating at a temperature of 40 ℃ for 20 min, and centrifuging the extracted solutions at 4500 r/min for 10 min. The samples were purified by MAX, and the sample matrix effect was found to be lesser than 1.6%-10.8%. Under the optimum conditions, the calibration curves of the three oryzanols showed good linearity (correlation coefficients

Progesterone functions as an endocrine-disrupting compound. Imitating endogenous hormones disrupt the animals' hormone levels. The potential hazard of progesterone in milk cannot be neglected. Thus, research has focused on establishing an efficient and convenient pretreatment and analytical approach. In this study, a metal-organic framework (MOF) material UiO-67 was prepared, which possessed a large specific surface area and excellent stability. It was employed to enrich and purify trace progesterones in a complex milk matrix as a filler to integrate the solid phase extraction column. An approach based on MOF was developed using ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS). This approach could simultaneously determine seven kinds of progesterone residues in milk. The element spectra of UiO-67 were first measured and analyzed using X-ray photoelectron spectroscopy. The chemical interaction between UiO-67 and progesterone was proved by comparing the changes in binding energy and relative contents of functional groups, and the adsorption efficiency of 1 mg/L and 5 mg/L progesterones by UiO-67 was studied. The adsorption efficiencies of UiO-67 for 1 mg/L and 5 mg/L progesterones were 99.73%-99.95% and 88.87%-99.23%, respectively, according to the results. It proved the efficient adsorption of UiO-67 to progesterones and ensured that subsequent studies went smoothly. Furthermore, key parameters, such as the amount of sorbent, elution solvent type, and pH value, were examined and optimized to obtain optimal extraction recovery of the progesterones. Spiked concentrations of 50 μg/L were employed for extraction optimization. All experiments were performed three times. It also evaluated the matrix effect on mass spectrum signal of the progesterones. The optimized results showed that the seven progesterones could be satisfactorily recovered when the amount of adsorbent was 40 mg, pH value of the sample solution was 5, and elution solution was 5-mL acetone. Additionally, the matrix effect of progesterone in the milk sample was20%. The matrix effect could be neglected using the aforementioned approach to extract and purify progesterones in milk. Finally, the seven progesterones showed good linearity between 1 and 100 μg/L under the optimized conditions, with linear correlation coefficients values0.99. The limits of detection (LODs) ranged from 0.06 to 0.30 μg/L, and limits of quantification (LOQs) ranged from 0.19 to 1.0 μg/L, respectively. At various concentration levels of progesterones in milk, the recoveries were 87.10%-105.58%, with relative standard deviations of 2.66%-9.64%. Most importantly, the approach was successfully employed to determine progesterone levels in milk samples, with results in good agreement with the standard SN/T 1980-2007. The proposed approach had the advantages of high sensitivity and satisfactory accuracy compared with the reported pretreatment and detection approaches of progesterone in milk. Satisfactory experimental results can be obtained without the calibration by isotope inner standard. Meanwhile, considering the excellent performance of MOF materials in reducing matrix interference in complex samples, such the application of materials offers a new approach. It can be employed to enrich and detect hazards in a complex matrix in the future.

Radioactive iodine isotopes play a pivotal role in radiopharmaceuticals. Large-scale production of multi-patient dose of radioiodinated nuclear medicines requires high concentration of radioiodine. We demonstrate that tetrabutylammonium chloride and methyltrioctylamonium chloride are effective phase transfer reagents to concentrate iodide-124, iodide-125 and iodide-131 from the corresponding commercial water solutions. The resulting concentrated radioiodide, in the presence of either phase transfer reagent, does not hamper the chemical reactivity of aqueous radioiodide in the copper (II)-mediated one-pot three-component click chemistry to produce radioiodinated iodotriazoles.

[EN] In the present work, a target analysis method for simultaneously determining 24 diverse endocrine-disrupting compounds (EDCs) in urine (benzophenones, bisphenols, parabens, phthalates and antibacterials) was developed. The target analysis approach (including enzymatic hydrolysis, clean-up by solid-phase extraction and analysis by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS)) was optimized, validated and applied to volunteers' samples, in which 67% of the target EDCs were quantified. For instance, benzophenone-3 (0.2-13 ng g(-1)), bisphenol A (7.7-13.7 ng g(-1)), methyl 3,5-dihydroxybenzoate (8-254 ng g(-1)), mono butyl phthalate (2-17 ng g(-1)) and triclosan (0.3-9 ng g(-1)) were found at the highest concentrations, but the presence of other analogues was detected as well. The developed target method was further extended to suspect and non-target screening (SNTS) by means of LC coupled to high-resolution MS/MS. First, well-defined workflows for SNTS were validated by applying the previously developed method to an extended list of compounds (83), and then, to the same real urine samples. From a list of approximately 4000 suspects, 33 were annotated at levels from 1 to 3, with food additives/ingredients and personal care products being the most abundant ones. In the non-target approach, the search was limited to molecules containing S, Cl and/or Br atoms, annotating 4 pharmaceuticals. The results from this study showed that the combination of the lower limits of detection of MS/MS and the identification power of high-resolution MS/MS is still compulsory for a more accurate definition of human exposome in urine samples. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work has been financially supported by the Ministry of Science and Innovation of the Spanish Government through project PID2020-117686RB-C31, and by the Education Department of the Basque Government as a consolidated group of the Basque Research System (IT1213-19).

A new sensitive and selective methods was developed to quantify different types of pesticides and their degradation products in sediment. The method developed was optimized and modified based on the accelerated solvent extraction, followed by the solid-phase extraction clean-up technique. High-performance liquid chromatography coupled with mass spectrometry was used for analysis. The influence of various parameters on the extraction process was investigated, including the extraction temperature, extraction solvent, purification column and purification solvent, etc. Under the optimal conditions, the relative recoveries of the pesticides and their degradation products ranged from 80 to 106% for spiked blank sediment and environmental sediment samples with relative standard deviations of 1-9%. The method displayed low method detection limits for both sediment matrices and achieved good linearity over the tested range of concentrations. The physical and chemical properties of sediment showed that high content of sediment water content and humic acid would affect the extraction efficiency of sample pretreatment. The method was applied to environmental sediment to quantify pesticide residues in the samples. Based on the instrument and method performance validation results, the developed methods can be applied in environmental pesticide residue analysis, thus providing a scientific method for the detection of sediment samples.

Vancomycin is a glycopeptide antibiotic used to treat infections caused by Gram-positive bacteria. Due to the narrow therapeutic index of vancomycin, it is necessary to develop a sensitive and reliable analytical method to monitor the drug concentration in plasma. A novel method based on surface molecularly imprinted solid-phase extraction combined with liquid chromatography-tandem mass spectrometry for the determination of vancomycin in plasma sample was developed. The plasma sample was cleaned up through the solid-phase extraction process before the analysis. The calibration standard of vancomycin in plasma ranged between 1 and 100 ng/mL, and the correlation coefficient (r) was 0.9993. The average recoveries were from 94.3 to 104.0%, and the precision was less than 10.5%. The limit of detection and limit of quantification were 0.5 ng/mL and 1 ng/mL, respectively. The method validated was successfully used for the detection of vancomycin in mice after oral administration.

A simple analytical method for the extraction and determination of three β-lactam antibiotics in chicken tissues and feather samples was developed and validated using solid phase extraction (SPE) and liquid chromatography-ultraviolet, LC-UV, detection. The analytes were extracted with strong anion exchange (SAX) cartridges for the extract clean-up and enrichment before introduction into the LC system. The validation was carried out based on the recommendations from Commission Decision 2002/657/EC. Under optimised conditions, the proposed method offers correlation coefficients of r2 ≥ 0.9991 for all the studied analytes in both matrices. Percent recovery results were found to vary between 79.7-101.8% and 94.2-101.6% for chicken feathers and tissues, respectively, with the relative standard deviation, RSD < 8.4%. The limits of detection (LOD) were in the range of 0.1-0.13 µg kg-1 and 0.1-0.15 µg kg-1 while the limits of quantification (LOQ) were in the range of 0.3-0.38 µg kg-1 and 0.3-4.5 µg kg-1 in chicken feathers and tissues, respectively. The proposed method offers good sensitivity and selectivity and all the results demonstrating that the method would be widely used for determination of β-lactam antibiotics and other trace level antibiotics residues having similar physical and chemical properties in the matrices of varying origins. KEY WORDS: Chicken tissues, Chicken feathers, β-Lactams, Solid phase extraction, LC-UV Bull. Chem. Soc. Ethiop. 2022, 36(3), 503-519. DOI: https://dx.doi.org/10.4314/bcse.v36i3.2 &nbsp

In the present research, an ultrasound-assisted magnetic solid-phase extraction coupled with a gas chromatography-mass spectrometry hybrid system was developed for the extraction/determination of trace amounts of polycyclic aromatic hydrocarbons in high-consumption soft drinks and non-alcoholic beers in Iran using magnetite graphene oxide adsorbent. The magnetite graphene oxide was characterized by scanning electron microscope, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and vibrating-sample magnetometer techniques. The highest extraction recovery (73.05%-95.56%) and enrichment factor (90.65-106.38) were obtained at adsorbent mass: 10 mg, adsorption time: 30 min, salt addition: sodium chloride 10% w/v, desorption time: 20 min, eluent type: hexane: acetone (1:1, v/v), and desorption solvent volumes: 200 μl. Under optimum conditions, the linearity range for polycyclic aromatic hydrocarbons determination was 0.2-200 ng/ml with a coefficient of determination 0.993, the limit of detection = 0.09-0.21 ng/ml, the limit of quantitation = 0.3-0.7 ng/ml, and relative standard deviation 8.1%, respectively. Relative recoveries in spiked real samples ranged from 94.67 to 109.45% with a standard deviation 6.05%. The proposed method is effective, sensitive, and reusable and it is promising for the analysis of polycyclic aromatic hydrocarbons residues in environmental samples.

Introduction Mycotoxins are toxic metabolites produced by fungi that commonly contaminate foods. As recommended by the World Health Organization, total diet study (TDS) is the most efficient and effective way to estimate the dietary intakes of certain chemical substances for general populations. It requires sensitive and reliable analytical methods applicable to a wide range of complex food matrices and ready-to-eat dishes. Objectives A novel strategy with high selectivity and sensitivity, incorporating three methods based on ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS), was designed for measuring 43 mycotoxins in dietary samples in a China TDS. Methods The 43 mycotoxins were divided into 3 groups for analysis to achieve better performance. For each group, an UHPLC-MS/MS method was developed to determine the target compounds after clean-up by solid phase extraction. A total of 21 isotope internal standards were employed for accurate quantitation. Method validation in terms of linearity, selectivity, sensitivity, accuracy, and precision was performed for all the 43 mycotoxins in 12 complex food matrices. Results The limits of detection (LODs) and limits of quantitation (LOQs) were 0.002–1 ng mL−1 and 0.006–3 ng mL−1, respectively. The method recoveries of the 43 mycotoxins spiked in 12 food categories were in the range of 60.3%–175.9% after internal standard correction, with relative standard deviations (RSDs) below 13.9%. For practical application, this method was utilized for 72 dietary samples collected from 6 provinces in the 6th China TDS. More than 80% of the samples were found contaminated by mycotoxins. DON, SMC, FB1, ZEN, BEA, ENNB1, and ENNB were most detected. Conclusions The proposed methods with high sensitivity, accuracy, and robustness provide powerful tools for multi-mycotoxin monitoring and dietary exposure assessment, allowing 43 mycotoxins, including some emerging mycotoxins, to be accurately investigated in a total diet study for the first time.

Due to the harmful effects of estrogens and their prevalence in animal foods, accurate analysis of estrogen levels in animal foods is imperative in order to effectively assess food safety risks and ensure consumer safety. Therefore, a rapid and accurate method based on PRiME HLB solid phase extraction (SPE) cartridge purification and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed to determine nine estrogen residues in bullfrogs. The nine estrogens included estriol (E3), 17

Nitroimidazoles (NMZs) are a crucial group of antibacterial compounds from a historical perspective. In the past, they were used for treating and preventing parasitic infections in fish. Benzodiazepines (BZDs) are second-generation sedative-hypnotics. Some fish farmers or vendors use them illegally to keep aquatic products fresh during the transportation of aquatic animals. Aquatic products are one of the most common food sources of protein and can be contaminated by NMZs and BZDs, which could impact humans through the food chain. Until recently, there was limited information on the simultaneous determination of NMZs and BZDs. Thus, it is critical to accurately quantify NMZs and BZDs for risk assessment and risk monitoring of food safety. For the simultaneous determination of five nitroimidazoles and six benzodiazepines in aquatic products, a new approach based on the dispersive solid-phase extraction (dSPE) coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed. First, the samples were extracted with acetonitrile containing 1% (v/v) ammonium hydroxide, and the extracts were purified using dSPE with C18 and primary secondary amine sorbents. Second, the extracts were collected and dried at 45 ℃ under nitrogen flow. Finally, the extracts were redissolved in 1 mL methanol-water (1∶9, v/v) mixture, filtered through a nylon-66 microfiltration membrane, and analyzed using UHPLC-MS/MS. The separation of compounds was conducted on a Kinetex F5 column (100 mm×3.0 mm, 2.6 μm) using gradient elution with 1% (v/v) formic acid aqueous solution and methanol as the mobile phase. The analytes were detected using MS/MS with positive electrospray ionization (ESI

17 pages, 5 figures.-- This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY), Our current knowledge of the chemical composition of ocean dissolved organic matter (DOM) is limited, mainly because of its extreme molecular diversity, low concentration of individual compounds and the elevated ionic strength of ocean waters. As a result, many analytical methods require a previous extraction step. The efficiency and selectivity of the extraction method defines the representativeness of the extracted DOM fraction. Nowadays, the most widespread procedure for concentrating DOM is solid phase extraction (SPE) using styrene divinyl benzene polymer cartridges (PPL). Here, we investigate the effect of SPE-PPL on DOM elemental and optical properties to assess the efficiency and selectivity of this extraction method on water samples from the main intermediate and deep water masses of Arctic, Mediterranean and Antarctic origin present in the Cape Vert Frontal Zone (CVFZ, NW Africa). Furthermore, North and South Atlantic Central waters converge in this area and coastal DOM is injected by the giant upwelling filament of Cape Blanc. On one side, the colored fraction of DOM (CDOM) presented extraction efficiencies comparable to that of the bulk dissolved organic carbon (DOC), but decreased significantly with increasing wavelength, suggesting an affinity of PPL cartridges for low molecular weight organic compounds. While the protein-like fluorescent fraction of DOM (FDOM) was also extracted with the same efficiency than DOC, the extraction efficiency of the humic-like fraction was comparatively much higher. On the other side, dissolved organic nitrogen (DON) extraction efficiencies were about half that of DOC. These contrasting extraction efficiencies of the different DOM pools indicated that the extracts were enriched in N-poor, low molecular weight and recalcitrant DOM, therefore showing less variability than the corresponding bulk DOM. Furthermore, DOC, DON, CDOM and FDOM extracted were not homogeneous through the water column but displayed certain significant differences among water masses in both efficiency and selectivity, This work was financed by the project FLUXES (grant number CTM2015-69392-C3-2-R), which was co-financed with FEDER funds. A pre-doctoral scholarship of the Xunta de Galicia (grant number IN606A-2019/026) and a contract associated to the project (e-IMPACT, PID2019-109084RB-C22) for: supported EJ-Ll. MN-C was supported by the project FERMIO (MINECO, CTM2014-57334-JIN) co-financed with FEDER funds

The determination of trace-level pharmaceuticals in water is generally performed using liquid chromatography combined with mass spectrometry, which is susceptible to interference from non-target substances, such as natural organic matter (NOM). In this study, the interference of NOM on the determination of 20 typical pharmaceuticals using solid-phase extraction followed by ultra-performance liquid chromatography-electrospray ionization-triple quadrupole mass spectrometry (UPLC-ESI-tqMS) was investigated with a combined consideration of recoveries, matrix effects, and process efficiencies. The results showed that the recoveries of most pharmaceuticals were not significantly affected by NOM concentrations of 1-50 mg/L. The matrix effects and process efficiencies decreased linearly with increasing logarithmic NOM concentrations, and the changes in matrix effects and process efficiencies both exhibited negative linear correlations with the pharmaceuticals' hydrophobicity (logK

Based on the size- and shape-selective sorption, 13X molecular sieves were developed as solid-phase extraction adsorbents to cleanup serum extract for the determination of polybrominated diphenyl ethers. The important parameters affecting the cleanup efficiency were investigated including the amount of sorbents, the type, and volume of solvents. Under the optimized conditions, the capacity for removing impurities was evaluated via gel permeation chromatography and gas chromatography with mass spectrometry. The results demonstrated that up to 99% of lipids in corn oil (13 mg) can be removed after cleanup, and endogenous compounds in serum can also be effectively eliminated. The cleanup efficiency is not only superior to hydrophile-lipophile balance column, but also close to acid silica gel and multifunction impurity sorbents. Generally, the developed cleanup method exhibited higher recovery for polybrominated diphenyl ethers with more than four bromines, especially for nona- and deca-brominated diphenyl ethers (99.1-117.8%). The cleanup method can be coupled with gas chromatography and tandem mass spectrometry for polybrominated diphenyl ethers analysis in human serum. The method detection limits were 0.01-0.27 ng/mL and average recovery was 50.9-113.3%, except 2,3',4',6-tetrabrominated, 2,3',4,4',6-pentabrominated, and 2,3,3',4,4',5',6-heptabrominated diphenyl ethers. 2,2',4,5'-Tetrabrominated diphenyl ethers had the highest detection frequency (95%) in human serum, whereas decabrominated diphenyl ethers had the maximum mean concentration (0.50 ng/mL).

Fortunately, the intentional contamination of food or water supplies out of criminal or terroristic motivation is a rather rare event. However, in the face of asymmetric warfare and as the consequences of such an event would be severe, food defence as a necessary supplement to food safety is gaining increased attention. While some progress has been made in developing non-target detection devices, the contamination of food or water supplies using readily available rodenticides may still be revealed only by complex analytical techniques. The presented study therefore aimed to develop a quick and easy screening method for the detection of sixteen globally common rodenticides in foodstuffs. Robust operation with limited personnel and analytical resources were one benchmark to be met by the method, which uses a slightly modified QuEChERS (quick, easy, cheap, effective, rugged, safe) protocol for dispersive solid-phase extraction and subsequent ion-pair chromatography with diode-array and fluorescence detection. Quantification limits were as low as 5 µg/kg with satisfying bias (recovery) and repeatability rates of 77 to 117% and 1.8 to 17.1%, respectively. The developed method provides reliable and robust detection of these deadly poisons at toxic concentrations, which was demonstrated impressively in an improvised assault scenario.

A simple, universal method to quantify soil methylmercury (MeHg) is not available. Here, we developed a solid-phase extraction-based method using gas chromatography mass spectrometry. MeHg was purified from the soil matrix using an optimized solid-phase extraction method, which reduced the use of organic solvents and eliminated the requirement for harmful reagents. The sample limit of quantification was 7.5 ng/g. MeHg recovery in the reference samples was 96.2%-102.6%; the intra- and inter-assay coefficients of variation were 3.4%-7.1% and 4.3%-7.1%, respectively, indicating high validation performance. This analysis method is simple as it can be performed using general-purpose reagents and instruments; has a high degree of trueness and accuracy; could be useful for soil MeHg quantification with improved sensitivity; and can provide reliable data to prevent MeHg contamination and improve food safety.

In the current study, the C18-modified halloysite was fabricated via silylation reaction and subsequently used as sorbent in matrix solid-phase dispersion (MSPD) for the extraction of bisphenol A and diethylstilbestrol from human placenta, followed by high-performance liquid chromatography-tandem mass spectrometry analysis. The as-prepared sorbent was characterized by scanning electron microscopy, energy-dispersive spectrometry, Fourier transform infrared spectroscopy, X-ray diffraction, and thermo-gravimetric analysis. Varied parameters such as methanol concentration in wash solvent, pH and salt concentration in elution solvent, elution volume, and mass ratio of sample to sorbent were optimized. The adsorption capacities of bisphenol A and diethylstilbestrol on the developed C18-modified halloysite were 6.3 and 14.2 mg g

In this study, a new method for the determination of fipronil and its three metabolites in environmental water samples was developed based on meltblown nonwoven fabric solid-phase extraction combined with gas chromatography-electron capture detection. As the core material of medical masks, meltblown nonwoven fabric is made of polypropylene superfine fibers which are randomly distributed and bonded together with a relatively large specific surface area and good permeability. Polypropylene as a high molecular hydrocarbon-based polymer has the characteristics of good hydrophobicity and lipophilicity, which can be applied for the separation and enrichment of hydrophobic substances in food, environment, and biological samples. The meltblown nonwoven fabric is soft and can fill the solid-phase extraction cartridge tightly. This aspect also makes it suitable to be used as an ideal solid-phase extraction sorbent. A series of parameters influencing the extraction efficiency were investigated, and under the optimized conditions, fipronil and its three metabolites had a good linear relationship in the range of 0.2-100 μg/L with a correlation coefficient R

Recently, pharmaceuticals and personal care products in the water environment exhibited potential risks to both human and aquatic organisms. In order to improve the sensitivity and accuracy of pharmaceutical detection, the polyimidazolyl acetate ionic liquid was synthesized by Radziszewski reaction and coated on cellulose filter papers as a thin-film extraction phase for extraction of non-steroidal anti-inflammatory drugs from water. The attenuated total reflection-infrared spectrometry, thermogravimetric analysis, and scanning electron microscope analyses demonstrated that the polyimidazolyl acetate ionic liquid was successfully prepared and attached to the surface of the cellulose filter paper through chemical bonding. The adsorption capacity of the homemade thin-film extraction material for the four non-steroidal anti-inflammatory drugs was greater than 8898 ng/cm

10 Pág., In this work, the preparation and evaluation of water-compatible molecularly imprinted polymers for triazines using 2-hydroxyethyl methacrylate and methacrylic acid as comonomers is described. Four sets of molecularly imprinted and non-imprinted polymers for propazine were prepared at varying monomer molar ratios (from 4:0 to 1:3), and evaluated for the recognition of several triazines directly in aqueous media. The evaluation was performed by loading 1 ml of an aqueous solution containing 500 ng of each selected triazine, washing with 500 μl of acetonitrile, and eluting with 500 μl of methanol followed by 2 × 500 μl of a solution of methanol containing 10% of acetic acid. Final determinations were performed by high-performance liquid chromatography-ultraviolet detection. Improvement in molecular recognition of triazines in water was obtained on those molecularly imprinted polymers incorporating 2-hydroxyethyl methacrylate in 3:1 or 2:2 molar ratios, being the former selected as optimum providing recoveries for propazine up to 80%. A molecularly imprinted solid-phase extraction protocol was developed to ensure that triazines-selective recognition takes place inside selective binding sites in pure water media. Finally, the developed method was successfully applied to the determination of the selected triazines in environmental waters providing limits of detection from 0.16 and the 0.5 μg/L concentration range., This article is based upon work from the National Thematic Network on Sample Treatment (RED-2018-102522-T) funded by the Spanish Ministry of Science, Innovation and Universities, and the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical Society.

Edible bird's nests (EBNs), a food of animal origin, are temporary nests built by swiftlets to foster their offspring. As EBNs and their products are widely accepted by consumers, the safety of hormones in EBNs has also received increasing attention. The establishment of a method for hormone analysis in EBNs and the investigation of hormone levels based on the analytical method are the most effective measures to eliminate any safety concerns. In this study, a multi-residue method was developed for the simultaneous determination of 45 hormones in EBNs, including estrogens, progesterones, androgens, and cortical hormones. EBN samples (1.0 g) were weighed into 50 mL polypropylene centrifuge tubes and mixed with 8 mL of pure water. Then, the samples were extracted twice with 15 mL of acetonitrile and ethyl acetate (1∶1, v/v) under ultrasonic-assisted conditions for 30 min, and the protein in the EBN samples was precipitated at 4000 r/min for 5 min. The clear supernatants were loaded onto a hydrophilic-lipophilic balanced (HLB) SPE column, which was previously activated with methanol (3 mL) followed by pure water (3 mL). The cartridge was washed with 3 mL of pure water and 3 mL of 50% methanol aqueous solution. The hormones were eluted with 3 mL of methanol. A rapid analysis was performed using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The hormones in the extracting solution were separated on a Phenomenex Kinetex C

A simple and efficient dithizone-functionalized solid-phase extraction (SPE) procedure, online coupled with high-performance liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry, was developed for the first time for enrichment and determination of ultra-trace mercury (Hg) species (inorganic divalent Hg (Hg(II)), methylmercury (CH3Hg(II)) and ethylmercury (C2H5Hg(II)) in cereals and environmental samples. In the proposed method, functionalization of the commercial C18 column with dithizone, enrichment, and elution of the above Hg species can be completed online with the developed SPE device. A simple solution of 2-mercaptoethanol (1% (V/V)) could be used as an eluent for both the SPE and HPLC separation of Hg species, significantly simplifying the method and instrumentation. The online SPE method was optimized by varying dithizone dose, 2-mercaptoethanol concentration, and sample volume. In addition, the effect of pH, coexisting interfering ions, and salt effect on the enrichment was also discussed. Under the optimized conditions, the detection limits of Hg species for 5 mL water sample were 0.15 ng/L for Hg(II), 0.07 ng/L for CH3Hg(II), and 0.04 ng/L for C2H5Hg(II) with recoveries in the range of 85%–100%. The developed dithizone-functionalized C18 SPE column can be reused after a single functionalization, which significantly simplifies the enrichment step. Moreover, the stability of Hg species enriched on the SPE column demonstrated its suitability for field sampling of Hg species for later laboratory analysis. This environment-friendly method offers a robust tool to detect ultra-trace Hg species in cereals and environmental samples.

Fe3O4-based materials are widely used for magnetic separation from wastewater. However, they often suffer from Fe-leaching behavior under acidic conditions, decreasing their activity and limiting sustainable practical applications. In this study, covalent organic frameworks (COFs) were used as the shell to protect the Fe3O4 core, and the Fe3O4@COF core-shell composites were synthesized for As(III) removal from acid wastewater. The imine-linked COFs can in situ grow on the surface of the Fe3O4 core layer by layer with [COFs/Fe3O4]mol ratio of up to 2:1. The Fe-leaching behavior was weakened over a wide pH range of 1-13. Moreover, such composites keep their magnetic characteristic, making them favorable for nanomaterial separation. As(III) batch adsorption experiments results indicated that, when COFs are used as the shell for the Fe3O4 core, a balance between As(III) removal efficiencies and the thickness of the COF shell exists. Higher As(III) removal efficiencies are obtained when the [COFs/Fe3O4]mol ratios were

In this study, the hydroxypropyl β-cyclodextrin hybrid monolithic material was fabricated and firstly applied as an adsorbent for dispersive solid-phase extraction coupled with high-performance liquid chromatography to detect trace-level seven fluoroquinolones in water samples. The prepared hydroxypropyl β-cyclodextrin hybrid monolithic material was characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and adsorption experiments, which showed excellent specific adsorption to the target fluoroquinolones. Under the optimized conditions, the extraction methodology showed satisfactory precision with relative standard deviations between 2.6% and 5.6%, good linearity (R

In this study, we developed a new method combining thin-layer ultrasonic extraction, efficient SPE purification, ultra-performance liquid chromatography separation, and high-resolution mass spectrometry characterization for seven amide herbicides in fishery products. In sample preparation, to rapidly increase the contact area between the fish meat and the extractant, the fish meat was smeared on a glass slide. This process resulted in quickly reaching the extraction equilibrium and relatively high extraction efficiency. In data analysis, a strategy for characterization and qualitative analysis was constructed by analyzing the fragmentation of amide herbicides using product ion scans. Isomeric pretilachlor and butachlor were separated chromatographically, while the coeluting isomers, alachlor and acetochlor, could be separated by differences in the fragmentation of their selected precursor ions. This method overcame the challenge of poor dispersion in the extractant caused by the high viscosity of fish meat, and the challenge of separation and characterization for isomers. Compared with other methods, the extraction efficiency was improved and the amide herbicides in aquatic products was characterized and quantified rapidly and accurately. Moreover, the qualitative information was much greater and provided an additional strategy for analytes identification. This rapid and accurate method will benefit workers involved in monitoring fishery.

The chemical analysis of odorous volatile thiols is intrinsically challenging. Substantial progress has been made in quantitative analysis of targeted thiols at ultra-trace concentrations (ng/L), but lesser analytical attention has been given to the qualitative screening of unknown thiols. This work presents a solid-phase extraction (SPE) method using a silver ion (Ag