Sustainable and green microextraction of organophosphorus flame retardants by a novel phosphonium‐based deep eutectic solvent

Comparison of the extractability of organophosphorus flame retardants in landfill media using organic and green solvents

Organic solvents are mainly used in the extraction of organophosphorus flame retardants (OPFRs) because of their availability and having been tested as good extracting solvents for most environmental pollutants. However, organic solvents are toxic, flammable, and costly. Hence, there is an ongoing quest for less hazardous chemicals such as green deep eutectic solvents (DES) that are cheap, recyclable, non-toxic and degradable in the environment, which can be used to extract organic pollutants such as OPFRs in environmental samples. This study assessed the extractability of OPFRs in municipal landfill leachate and sediment, using organic solvents and DES. Of the fourteen targeted OPFRs, 11 (80%) and 7 (50%) were detected in the leachate and sediment samples, using hexane; whereas 14 (100%) and 13 (90%) OPFRs were detected in the same order of samples using DES. The concentrations of OPFRs obtained for the leachate using optimum organic and DES ranged from below the limit of quantification (< LOQ)—516 ± 8.10 ng/L and < LOQ—453 ± 8.10 ng/L respectively. Correspondingly, the concentrations of OPFRs in sediment samples ranged from < LOQ—135 ± 2.89 ng/g dw and < LOQ—395 ± 2.24 ng/g dw, respectively. The results from this study, therefore, highlight the potential of DES to extract more OPFR from complex matrices such as landfill leachate and sediment. This finding infers that green hydrophilic DES can serve as good replacement for organic solvents such as hexane in liquid–liquid extraction (LLE) and solid–liquid extraction (SLE) techniques for landfill leachate and sediment.

Analysis of tamoxifen and its main metabolites in plasma samples of breast cancer survivor female athletes: Multivariate and chemometric optimization

A sensitive method based on liquid chromatography combined with a diode array detector was developed and validated to simultaneously determine tamoxifen, and its active metabolites N-desmethyltamoxifen, 4-hydroxytamoxifen, and endoxifen in human plasma samples. The green and sustainable vortex-assisted dispersive liquid-phase microextraction technique based on the natural hydrophobic deep eutectic solvent was used for the extraction and pre-concentration of the analytes. Chemometrics and multivariate analysis were used to optimize the independent variables, including the type and volume of deep eutectic solvent, extraction time, and ionic strength. Under optimal conditions, calibration curves were linear in a suitable range with the lower limits of quantification (0.8-10.0 μg L^-1 ), which covered the relevant concentrations of the analytes in plasma samples for a clinical study. Intra- and inter-day precision evaluated at three concentrations for the analytes were lower than 8.2 and 12.1 %, respectively. Accuracy was in the range of 94.9-104.7%. The applicability of the developed method on human plasma samples illustrated the range 45.1-72.8, 98.4-128.3, 0.9-1.2, and 2.7-6.1 μg L^-1 for tamoxifen, N-desmethyltamoxifen, 4-hydroxytamoxifen, and endoxifen, respectively. The validated method can be effective for the pharmacokinetics, pharmacodynamics, and therapeutic drug monitoring studies of tamoxifen and its main metabolites in biological fluids. This article is protected by copyright. All rights reserved.

Deep Eutectic Solvents as Promising Green Solvents in Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Droplet: Recent Applications, Challenges and Future Perspectives

Deep eutectic solvents (DESs) have recently attracted attention as a promising green alternative to conventional hazardous solvents by virtue of their simple preparation, low cost, and biodegradability. Even though the application of DESs in analytical chemistry is still in its early stages, the number of publications on this topic is growing. Analytical procedures applying dispersive liquid-liquid microextraction based on the solidification of floating organic droplets (DLLME-SFOD) are among the more appealing approaches where DESs have been found to be applicable. Herein, we provide a summary of the articles that are concerned with the application of DESs in the DLLME-SFOD of target analytes from diverse samples to provide up-to-date knowledge in this area. In addition, the major variables influencing enrichment efficiency and the microextraction mechanism are fully investigated and explained. Finally, the challenges and future perspectives of applying DESs in DLLME-SFOD are thoroughly discussed and are critically analyzed.

Sustainable green solvents for microextraction techniques: Recent developments and applications

The development and application of alternative green solvents in analytical techniques consist of trends in sample preparation, since this subject represents an important step toward sustainability in experimental procedures. This review is focused on the main theoretical aspects related to deep eutectic solvents (DES), switchable hydrophilicity solvents (SHS) and supramolecular solvents (SUPRAS). Recent applications are highlighted, particularly for the extraction of different analytes from environmental, biological and food matrices. Moreover, novel configurations are emphasized, aiming for efficient, automated and high-throughput procedures. This review also provides some critical points regarding the use of these solvents and their green aspects.

Validation of chemometric-assisted single-drop microextraction based on sustainable solvents to analyze polyaromatic hydrocarbons in water samples

Chemometric and statistic approaches were applied to optimize and validate headspace-single drop microextraction-based deep eutectic solvents combined with gas chromatography-mass spectrometry. The proposed technique was used for the pre-concentration, separation, and detection of polyaromatic hydrocarbons in aqueous samples. The efficacy of the independent variables on the extraction efficiency was studied via chemometric methods in two steps. The method exhibits good linearity for the analytes (R2 ≥ 0.9989). Under optimal conditions, the analytical signal was linear in the range of 0.01-50 μg L-1. The limit of detection and limit of quantitation were evaluated in the concentration range of 0.003-0.012 and 0.009-0.049 μg L-1, respectively. The precision consisting of repeatability and reproducibility were assessed by estimating the relative standard deviation (RSD%), and their values were found to be lower than 7.1% and 11.7%, respectively. Consequently, the proposed procedure was used to extract and analyze 19 polyaromatic hydrocarbons in real aqueous samples, which demonstrated satisfactory recoveries (94.40-105.98%).

Deep eutectic solvent-based headspace single-drop microextraction of polycyclic aromatic hydrocarbons in aqueous samples

An improved deep eutectic solvent (DES)-based headspace single-drop microextraction procedure has been developed as a green procedure for gas chromatography-mass spectrometric analysis of polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. The stability of the micro-drop was significantly improved using a DES as an extraction phase and a bell-shaped tube as a supporter. These strategies helped to perform the extraction process in higher temperatures and stirring rates. Finally, the back-extraction of the analytes into a proper solvent that is compatible with the chromatography system was applied. The efficacy of the independent variables on the extraction efficiency was evaluated via chemometric methods in two steps. The best result was obtained with choline chloride-oxalic acid at the molar ratio of 1:2, a stirring speed of 2000 rpm for 10 min as well as a sample temperature of 50 °C and with ionic strength prepared by using a 10% (w/v) NaCl. The method indicated a good linearity for the analytes (R²≥0.9989). Under optimal conditions, the analytical signal was linear in the range of 0.01-50 μg L^-1. Limit of detection (LOD) and limit of quantification (LOQ) were evaluated at the concentration levels of 0.003-0.012 and 0.009-0.049 μg L^-1, respectively. Intraday and interday precision for all targeted compounds was less than 7.2% and 11.3%, respectively. Consequently, the proposed procedure was efficiently applied to extract and analyze the 16 target compounds in real aqueous samples representing satisfactory recoveries (94.40-105.98%).