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Here, a zirconium-based metal organic framework-dispersive solid phase extraction method was established as an efficient, robust, and accurate approach for quantifying apixabanin human plasma samples prior to capillary electrophoresis with diode array detection. Various types of metal organic frameworks based on UiO-66-NH 2 were synthesized by altering modulators and solvents and applied as sorbents in the extraction procedure. Among the tested sorbents, UiO-66-NH 2 prepared in dimethylformamide in the presence of acetic acid was found to be the best sorbent in this method for the extraction of apixaban with high extraction efficiency comparable to other types of UiO-66-NH 2 metal organic frameworks. The extraction and preconcentration of apixaban were carried out by adding 5 mg of synthesized sorbent to a 5 mL sample solution, followed by vortexing for 3 min. After discarding the supernatant, the adsorbed analyte was eluted from the sorbent surface using 60 µL acetonitrile under vortexing for 2 min. The effective parameters of the offered method were optimized and validated using a one-parameter-at-a- time strategy. The detection and quantification limits of the method were 9.9 and 32 ng mL -1 in plasma and 1.5 and 4.9 ng mL -1 in deionized water, respectively. The method was linear ranging from 4.9 to 1000 ng mL -1 in deionized water and from 32 to 500 ng mL -1 in plasma, respectively. The enrichment factor and extraction recovery values were 44 % and 53 %, respectively. The relative standard deviations were ≤6.2 % for intra- and inter-day precisions. Finally, the proposed method was successfully employed to quantify apixaban in human plasma samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, a new method was used to evaluate the levels of four organochlorine pesticides in edible samples. In this method, a density tunable dispersive solid phase extraction procedure was coupled with gas chromatography-mass spectrometry. Rhodamine B was used as a sorbent, which was distributed throughout the oil matrix with the aid of evaporation of methanol. This process enabled the possibility of effective extraction and preconcentration of the target analytes. To achieve this goal, several factors affecting the extraction efficiency, including the type and volume of diluent, the amount of rhodamine B, the volume of methanol, and the temperature of the ultrasonic bath were carefully evaluated. This method provided low detection limits (from 0.21 to 0.36 ng g -1 ), wide linear range (1.1-100 ng g -1 ) and acceptable extraction recoveries (64-72%) and enrichment factors (102-115). The precision of the method was evaluated by calculating the relative standard deviation, which ranged from 3.6 to 6.8% for intra- and 3.1 to 8.8% for inter-day precisions. The investigated method reduced the interference of the matrix and provided the possibility of quantitative determination of the studied organochlorine pesticides in various oil samples (canola, corn, sunflower, and olive). This method introduced a reliable analytical tool for the monitoring of the pesticide residues in different oil samples by providing capabilities such as simplicity, sensitivity, and compatibility with the environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, a new magnetic nanocomposite comprised of a molecularly imprinted polymer, metal organic framework, and covalent organic framework was synthesized and used in the dispersive solid-phase extraction of montelukast from plasma and urine samples. The extracted analyte was then analyzed using liquid chromatography-tandem mass spectrometry. The drug extraction process involved adding the synthesized nanocomposite to the biological sample. After vortexing, the solid particles were collected using an external magnet. The adsorbed analyte was subsequently eluted with acetonitrile. By combining of the developed method with liquid chromatography-tandem mass spectrometry, low limits of detection (0.04 and 0.05 ng mL -1 in urine and plasma, respectively) and quantification (0.14 and 0.16 ng mL -1 in urine and plasma, respectively), a wide linear range (0.14-300 and 0.16-300 ng mL -1 in urine and plasma, respectively), acceptable relative standard deviations for intra- and inter-day precisions (≤6.3 %), and good extraction recoveries (75 and 72 % in urine and plasma samples, respectively) were achieved., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this research, a new covalent organic framework was synthesized and utilized as a coating in thin film microextraction for the extraction of apixaban from plasma samples. This coating was applied to the mesh modified through immersion in a HF solution. The extracted drug was then analyzed using liquid chromatography-tandem mass spectrometry. By combining the high specific surface area and selectivity of the covalent organic framework, along with integrating the innovative thin film microextraction method and a sensitive analysis system, an efficient analytical approach was achieved. The target analyte was preconcentrated and extracted by immersing of the covalent organic framework-coated mesh as an absorbent into the biological sample. Subsequently, a sonication process was conducted for a specific duration. Following this, the extracted analyte was desorbed using acetonitrile as the elution solvent. The effective parameters of the proposed technique were optimized by using "one-parameter-at-a-time" strategy and the optimal conditions were selected. By integrating the developed method notable achievements were made in the terms of low limits of detection and quantification (0.17 and 0.56 µg/L, respectively), a wide linear range (0.05-250 µg/L), intra- and inter day precisions (with relative standard deviations of ≤14 %), as well as satisfactory extraction recoveries (53 % and 54 % in plasma and deionized water, respectively). Hence, it can be concluded that the introduced technique exhibits high efficiency and reliability when applied to biological samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In the present work, a new microextraction procedure combined with gas chromatography-mass spectrometry has been developed for the analysis of several aliphatic amines from urine sample. The sample preparation method was a continuous homogenous liquid phase microextraction that was based on in-situ preparation of 4-chlorophenol: choline chloride deep eutectic solvent. The deep eutectic solvent was prepared by passing the mixture of related compounds through a syringe barrel filled with exothermic salts (calcium chloride and potassium bromide). The released heat by dissolving the salts and increasing the solution ionic strength assists the formation of the deep eutectic solvent. The influence of various factors on the efficiency of the proposed procedure including salts amount, flow rate, pH, salting-out effect, and extraction solvent volume was studied. The calibration curves were linear broadly over the concentration range of 1.2-250 ng mL -1 with coefficient of determinations ≥0.996. The enrichment factors were in the range of 188-246 and the limits of detection and quantification were 0.16-0.37 and 0.56-1.2 ng mL -1 , respectively. Based on the results, the offered method was sensitive, rapid, eco-friendly, and efficient for extracting and determining aliphatic amines in urine samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The presence of heavy metals in crude oil can create different problems on the oil processing and devices as well as pollution of the environment. Establishment of sample preparation methods for the extraction of metals from crude oil is the bottleneck of a successful determination method due to high hydrophobicity and complexity of crude oil matrix. In this study, a dispersive solid phase extraction procedure was developed for the simultaneous extraction of sixteen metal ions based on in-situ formation of an adsorbent in the sample solution. For this purpose, a suitable amount of dithiooxamide was dissolved in an organic solvent and was injected into the sample solution. By this action, dithiooxamide was re-precipitated in the sample solution and adsorbed the ions. The solid particles were separated and then the ions were eluted by a few microliters of choline chloride: 5-amino-8-hydroxyquinoline deep eutectic solvent under sonication. The presented method was validated and broad linear ranges (7.56-50000 ng g -1 ) were obtained for calibration curves with coefficient of determination ≥0.992. Acceptable limits of detection (0.003-2.32 ng g -1 ) and quantification (0.009-7.56 ng g -1 ) were achieved. Good precision (relative standard deviation less than or equal to 4.3% for intra and inter-day precisions) and acceptable extraction recoveries (66-91%) were also obtained. Seven crude oil samples were analyzed and ten metal ions were determined successfully. The method was compared with the methods reported in literature and it was found that the data obtained by this method were reliable and accurate., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

A simple, green, rapid, and efficient ligandless dispersive liquid-liquid microextraction procedure based on solidification of a ternary deep eutectic solvent has been proposed for the extraction of trace amounts of Cd(II), Cu(II), and Pb(II) ions in milk samples prior to their determination by flame atomic absorption spectrometry. Initially, a suitable mole ratio of sorbitol, menthol, and mandelic acid are mixed in a test tube, and after heating, a deep eutectic solvent with low density compared to water is formed. The synthesized solvent is used as a chelating agent and an extraction solvent in the extraction of some heavy metal ions from milk samples. The influence of several effective parameters on the responses and extraction recoveries of the analytes was investigated. Under the optimum experimental conditions, the linear ranges were in the ranges of 1.0-40 μg L -1 for Cd(II) and Pb(II), and 1.0-25 μg L -1 for Cu(II). The obtained relative standard deviations (n = 6, C = 2.5 μg L -1 of each cation) and detection limits were in the ranges of 3.4-4.1% and 0.38-0.42 μg L -1 , respectively. Finally, the developed method was successfully applied for the determination of Cd(II), Cu(II), and Pb(II) ions in different milk samples., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A new sample preparation method has been developed for extraction and preconcentration of some heavy metal cations in aqueous samples using cyclohexylamine-based homogeneous liquid-liquid microextraction. In the proposed method, cyclohexylamine was used as both the complexing agent and the extraction solvent. For this purpose, cyclohexylamine at µL level was initially added into an aqueous solution containing Co(II), Ni(II), and Cu(II) ions which was placed in a glass test tube. The mixture was shaken for forming a homogeneous solution. Then sodium chloride was added to the solution. After shaking manually again, the test tube was placed in a water bath thermostated at 70°C. Due to lower solubility of cyclohexylamine at the elevated temperature, a cloudy solution was formed. The fine droplets of cyclohexylamine containing cation-cyclohexylamine complexes were collected on the top of the aqueous phase by centrifuging. The enriched analytes in the upper phase were determined by graphite furnace atomic absorption spectrometry. Several variables possibly affecting the extraction efficiency were investigated and optimized. Under the optimum conditions the calibration curves were linear in the ranges of 80-1000, 40-700, and 80-800ngL -1 for Co 2+ , Ni 2+ , and Cu 2+ , respectively. Repeatability of the proposed method, expressed as relative standard deviation, ranged from 3.3% to 5.2% (n = 6, C = 200ngL -1 ). Moreover, the obtained detection limits of the selected analytes were in the range of 15.3-37.7ngL -1 . The accuracy of the developed procedure was verified by analyzing a certified reference material, namely NRCC-SLRS4 Riverine water. Finally, the proposed method was successfully applied for the simultaneous analysis of the selected analytes in environmental water samples., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this study, a developed technique was reported for extraction and pre-concentration of methamphetamine (MAMP) and 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) from urine samples using molecularly imprinted-solid phase extraction (MISPE) along with simultaneous derivatization and dispersive liquid-liquid microextraction (DLLME). Molecularly imprinted microspheres as sorbent in solid phase extraction (SPE) procedure were synthesized using precipitation polymerization with MAMP as the template. Aqueous solution of the target analytes was passed through MAMP-MIP cartridge and the adsorbed analytes were then eluted with methanol. The collected eluate was mixed with butylchloroformate which served as the derivatization reagent as well as the extraction solvent. The mixture was immediately injected into deionized water. After centrifugation, 1 μL of the settled organic phase was injected into gas chromatography-flame ionization detection (GC-FID) or gas chromatography-mass spectrometry (GC-MS). Various experimental parameters affecting the performance of both of the steps (MISPE and DLLME) were thoroughly investigated. The calibration graphs were linear in the ranges of 10-1500 ng mL(-1) (MAMP) and 50-1500 ng mL(-1) (MDMA), and the detection limits (LODs) were 2 and 18 ng mL(-1), respectively. The relative standard deviations (%RSDs) obtained for six repeated experiments (100 ng mL(-1) of each drug) were 5.1% and 6.8% for MAMP and MDMA, respectively. The relative recoveries obtained for the analytes in human urine samples, spiked with different levels of each drug, were within the range of 80-88%., (Copyright © 2012 Elsevier B.V. All rights reserved.)