Preparation and characterization of various chitin-glucan complexes derived from white button mushroom using a deep eutectic solvent-based ecofriendly method.

Deep eutectic solvents (DESs) have gained great interests as ecofriendly and safe solvents in diverse areas. Herein, various chitin-glucan complexes (CGCs) were prepared from white button mushroom (Agaricus bisporus) using DESs. Ultrasonication of mushroom in five DESs yielded two types of CGCs from each DES, one from the DES-insoluble residue (DES_P) and another from the DES-soluble extract (DES_S). The ten resulting CGCs with varying chitin-to-ß-glucan ratios were compared with alkali-insoluble matter (AIM), chemically prepared using NaOH. BU_S and BU_P, prepared using BU comprising betaine and urea, were obtained in the highest yields with reasonably low protein and mineral contents. Despite different acetylation degrees (77.3% and 57.3%, respectively), BU_S and BU_P both degraded at 318 °C and showed remarkably low crystallinity (32.0% and 37.0% for BU_S and BU_P, respectively) compared to AIM, commercial chitin, and the reported CGCs. The surface of BU_S and BU_P was very porous and rough compared with AIM as a result of reduced H-bonds and lowered crystallinity. The DES-based method can potentially enable the preparation of advanced biomaterials from mushrooms under mild and ecofriendly conditions.

Applications of deep eutectic solvents to quantitative analyses of pharmaceuticals and pesticides in various matrices: a brief review.

Pharmaceuticals and pesticides are important analytes of interest in clinical, environmental, and food analyses for ensuring public health. Sample pretreatment steps are often prerequisites for the quantitative analysis of these compounds, which are generally present in low concentrations in samples with complex matrices. In compliance with the current trend towards green analytical chemistry, the replacement of conventional toxic organic solvents with ecofriendly and safe solvents has been pursued in developing sample pretreatment methods. Subsequent to several reports in 2017, deep eutectic solvents (DESs) have been increasingly applied as desirable alternative solvents in numerous types of sample pretreatment methods for the analysis of pharmaceuticals and pesticides. The present review summarizes analytical methods involving DESs as extraction solvents and as the reaction media or functional materials for preparing adsorbents to quantify pharmaceuticals and pesticides in various matrices.

In situ formation of thymol-based hydrophobic deep eutectic solvents: Application to antibiotics analysis in surface water based on liquid-liquid microextraction followed by liquid chromatography.

A simple and ecofriendly sample preparation method was developed for quantifying fluoroquinolone (FQ) antibiotics in surface water. Seventeen combinations of monoterpenes (menthol, thymol, and camphor), fatty acids (heptanoic, octanoic, nonanoic, and decanoic acids), and a benzoate ester (salol) were utilized for the in situ formation of hydrophobic deep eutectic solvents (hDESs) for liquid-liquid microextraction (LLME). The hDES comprising thymol and heptanoic acid (HA) exhibited the highest extraction efficiency for ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin. Optimization via the one-variable-at-a-time strategy revealed that a 2:1 ratio of thymol to HA yielded the highest efficiency for antibiotic extraction at pH 4-7. Further, response surface methodology-based optimization suggested that the optimal extraction conditions involved the use of appropriate amounts of thymol and HA to generate 100 µL of hDES in 10 mL of aqueous sample with incubation at 52 °C for 5 min, followed by automated shaking for 1 min. The collected hDES phase was diluted and subjected to liquid chromatography-ultraviolet detection analysis. The established method based on in situ formation of hDES coupled with shaker-assisted LLME (in situ hDES-SA-LLME) was validated. The method was specific and showed good linearity in the 15-3000 ng mL-1 concentration range (r2 ≥ 0.9997), with a limit of detection of 3.0 ng mL-1, limit of quantification of 9.0 ng mL-1, accuracy of 84.1-113.65%, and intra-day and inter-day precision of ≤7.78% RSD and ≤7.91% RSD, respectively. The method was successfully applied to three different types of real surface water samples. Without toxic volatile organic solvents, the developed method allows for safe and rapid, yet reliable, analysis of FQ antibiotics.