Salt-induced homogenous solid phase extraction of hydroxylated metabolites of polycyclic aromatic hydrocarbons from urine samples using a deep eutectic solvent as an elution solvent prior to HPLC-FLD analysis

Acid-base reaction-based dispersive solid phase extraction of favipiravir using biotin from biological samples prior to capillary electrophoresis analysis

In this study, an acid-base reaction-based dispersive solid-phase extraction method was developed for the extraction of favipiravir from deionized water, plasma and urine samples prior to its determination using a capillary electrophoresis-diode array detector. The target analyte was extracted from the samples using biotin as a green adsorbent. To reach this goal, the pH of the solution was first adjusted to 9.0 (using borate buffer), and the ionic strength of the solution was enhanced by adding sodium chloride (2.5%, w/v). Thereafter, an appropriate amount of biotin was dissolved in the solution and a homogenous phase was obtained. By adding hydrochloric acid to the solution, an acid-base reaction occurs via protonation of biotin, which decreases its solubility. During this procedure, the analyte was adsorbed onto the tiny particles of the produced adsorbent dispersed into the solution. The resulting mixture was sonicated to facilitate the adsorption of the analyte onto the adsorbent surface. After the collection of biotin particles through centrifugation, the analyte was eluted using acetonitrile and then used in the determination stage. Under the optimal extraction conditions, the calibration curve was linear from 250 to 3000 ng mL-1 with a coefficient of determination of 0.9968. Low limit of detection, and quantification, good repeatability on the same day and different days (relative standard deviation ≤ 8.2%), and acceptable extraction recovery were accessed. The applicability of the method was examined by performing it on spiked plasma and urine samples, and its performance was verified.

Development of homogeneous dispersive solid phase extraction using albumin as a green sorbent and its combination with dispersive liquid-liquid microextraction: application in extraction of pesticides from fruit juices

In the current study, salt- and pH-induced homogeneous dispersive solid phase extraction was developed using albumin as a sorbent for the extraction of some pesticides (diazinon, diniconazole, haloxyfop-R-methyl, and hexaconazole) from fruit juice of orange, pomegranate, and barberry. The extracted analytes were more concentrated by dispersive liquid-liquid microextraction to obtain high enrichment factors and low detection limits prior to their determination by gas chromatography-mass spectrometry. In the extraction process, human serum albumin solution was added to the sample solution at the μL-level and a homogeneous solution was obtained. Then, albumin was precipitated into the solution by adding an inorganic salt and decreasing the solution pH. By doing so, the analytes were adsorbed by albumin effectively due to their high adsorption capacity and large surface area. Following this, the pesticides were eluted from the albumin sorbent using an elution solvent and used in a dispersive liquid-liquid microextraction step. Under the optimum extraction conditions, low limits of detection and quantification were achieved in the ranges of 0.02-0.04 and 0.07-0.13 ng mL-1, respectively. The calibration curves were linear in the range of 0.13-250 ng mL-1. Relative standard deviation as a criterion for precision and the method repeatability were in the ranges of 2.9-4.2% for intra- (n = 5, C = 5 or 50 ng mL-1) and 3.2-5.2% for inter-day (n = 5, 50 ng mL-1) precisions. The enrichment factors and extraction recoveries were in the ranges of 390-460 and 78-92%, respectively. Finally, the offered procedure was applied for the analysis of pesticide residues in some fruit juice samples.

Development of deep eutectic solvent-based microwave-assisted extraction combined with temperature controlled ionic liquid-based liquid phase microextraction for extraction of aflatoxins from cheese samples

In this study, for the first time, a deep eutectic solvent-based microwave-assisted extraction was combined with ionic liquid-based temperature controlled liquid phase microextraction for the extraction of several aflatoxins from cheese samples. Briefly, the analytes are extracted from cheese sample (3 g) into a mixture of 1.5 mL choline chloride:ethylene glycol deep eutectic solvent and 3.5 mL deionized water by exposing to microwave irradiations for 60 s at 180 W. The liquid phase was taken and mixed with 55 μL 1-hexyl-3-methylimidazolium hexafluorophosphate. By cooling the solution in the refrigerator centrifuge, a turbid state was obtained and the analytes were extracted into the ionic liquid droplets. The analytes were determined by high-performance liquid chromatography equipped with fluorescence detector. Low limits of detection (9-23 ng kg-1 ) and quantification (30-77 ng kg-1 ), high extraction recovery (66%-83%), acceptable enrichment factor (40-50), and good precision (relative standard deviations ≤ 5.2%) were obtained using the offered approach. These results reveal the high extraction capability of the method for determination of aflatoxins in the cheese samples. In this method, there was no need for organic solvents and it can be considered as green extraction method.