| dc.description.abstract | Currently, Benzotriazoles (BTRs) and Benzothiazoles (BTs) have been widely used in industrial synthesis, drug development, and household cleaner manufacturing, and characterized as the high production volume (HPV) chemicals. The studies have been found that BTRs and BTs can cause mutations in bacterial cells, damage to animals and plants, as well as are potentially carcinogenic to humans. Moreover, due to the high polarity and high water solubility of BTRs and BTs, they are easy to remain in the environmental water bodies, and they endanger the environment and human health through environmental distribution and bioconcentration. Therefore, it is necessary to develop a simple and rapid detect method to determine BTRs and BTs in our environmental system.
Deep Eutectic Solvents (DES), a group of novel “green” solvents, formed by mixing quaternary ammonium salts with hydrogen bond donor at various molar ratios. In this study, Choline Chloride was used as the quaternary ammonium salt and Phenol was chosen as the corresponding hydrogen bond donor. This type of DES was synthesized by mixing Phenol with Choline Chloride (at molar ratio 2:1).The mixture was stirred at 50 °C until a clear liquid was formed, which indicated that the preparation of DES solvent was completed.
In this study, DES was used as a polar extractant to extract nine polar BTRs and BTs compounds in environmental water samples by ultrasonic-assisted DES-liquid-liquid microextraction (USA-DES-LLME) and coupled with ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometer (UHPLC-qTOF-MS ) for detection technique.
The parameters of USA-DES-LLME were optimized by multivariate statistic Box-Behnken design (BBD) and analysis of variance (ANOVA). The optimal conditions were: 5 mL of water sample mixed with 1 mL of DES in a centrifuge tube, and sonicated for 20 min in ultrasonic bath, then added 0.5 mL of tetrahydrofuran (THF) to tube. After centrifugation at 3000 rpm for 7 min, the supernatant was collected, reconstituted with methanol to 500 μL, and 2 μL of the extractant was directly injected into UHPLC-qTOF-MS for detection.
The limits of detection (LODs) were 0.02 – 0.5 ng/mL. Intra-day and inter-day precisions (% RSD) for nine target analytes were less than 9%. The results displayed that the method was stable and reproducible. According to preliminary results, the total concentrations of BTRs ranged from n.d. to 40.9 ng/mL, and the total concentrations of BTs were n.d. to 57 ng/mL in our collected surface water samples. | en_US |