| 摘要: | 近年來，苯并三唑類化合物(Benzotriazoles，簡稱BTRs) 與苯並噻唑類化合物 (Benzothiazoles ，簡稱BTs)被廣泛應用於工業合成、藥物開發、家用清潔劑製造等領域。但研究發現，BTRs及BTs除了對動、植物具有危害外，也能使細菌細胞發生突變，對人類來說更是潛在致癌物質。另一方面，因BTRs和BTs的高極性、高水溶性特點，易殘留於環境水體中，經由環境流布、生物濃縮等效應，造成環境汙染及危害人體健康。因此有必要開發出一套快速、簡單的檢測方法檢測環境水體中BTRs和BTs的濃度。
深共熔溶劑(Deep Eutectic Solvents，簡稱DES)，為一綠色化學溶劑，主要由四級銨鹽搭配氫鍵供應者，在不同比例結合下會形成具極性的混合溶劑，可用來作為萃取極性待測物的萃取劑。本研究所使用的DES由四級銨鹽的氯化膽鹼(Choline Chloride)搭配苯酚(Phenol)做為氫鍵供應者。以Phenol : Choline Choride=2:1比例在溫度50℃下反應製備而成，使其由固體混合物呈現出溶液狀態。
本研究將上述製備的DES作為萃取劑，以超音波輔助深共熔溶劑液液微萃取法(Ultrasonic-assisted DES-liquid-liquid microextraction 簡稱USA-DES-LLME)，萃取環境水樣中九種BTRs和BTs，結合超高效液相層析串聯質譜儀 (UHPLC-qTOF-MS) 做定性及定量檢測。
本研究使用統計實驗設計 (Statistical experimental design) 法中的Box-Behnken design (BBD) 及變異數分析 (Analysis of variance, ANOVA)，找尋USA-DES-LLME的最佳化條件。其最佳化條件為：將5 mL的環境水樣、1 mL的DES 置於離心管中，以超音波震盪20分鐘，接著加入0.5 mL的四氫呋喃(Tetrahydrofuran，簡稱 THF)，再以3000 rpm離心7分鐘，取出分層的萃取液後，加入MeOH至500 μL，再取2 µL進樣至UHPLC-qTOF-MS中進行檢測。
九種BTRs和BTs的偵測極限介於0.02-0.5 ng/mL在Intra-day及
Inter-day的測試中，相對標準偏差 (RSD) 皆小於9 %，顯示此方法有良好的穩定性和再現性。在環境水樣中測得的BTRs總濃度介於n.d-40.9 ng/mL之間，而BTs總濃度介於n.d.-57 ng/mL之間。;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. |
