本研究開發一種靈敏、簡單且對環境友善的方法檢測不同茶湯中的八種 Benzotriazoles (BTRs) 和 Benzothiazoles (BTHs)。茶湯樣品的前處理以深共熔溶劑結合超音波震盪進行液液微萃取。深共熔溶劑為一個合成快速，對環境友善、低揮發性的萃取劑，其中的氯化膽鹼具生物相容性。氯化膽鹼和 4?氯酚以莫耳數比 1 : 3 形成疏水性的深共熔溶劑萃取茶湯中的待測物，再以超高效液相層析高解析度串聯式質譜儀 (UHPLC?QTOF?MS) 進行分析。 再最佳化時，以 Design expert 軟體進行最佳化模擬，首先以 Multilevel categoric design 進行種類實驗的最佳化，結果以深共熔溶劑比例1 : 3、萃取的機械力為超音波震盪、不冰浴直接離心，得到最佳回收率。接著，利用 Face-centered Central Composite Design 的多因子實驗設計和反應曲面法及多變量分析 (ANOVA) 進行各項變因的最佳化，結果以萃取劑的體積 800 μL、超音波溫度 55℃、超音波震盪的時間 5 分鐘為最佳回收率。接著離心之後利用甲醇定量至 1 毫升，最後取其中 2 μL 的樣品注入至 UHPLC?QTOF?MS。 將本研究將開發的方法進行偵測極限 (LOD) 及定量極限 (LOQ) 的分析，得到的濃度分別介於 0.1 ~ 7.5 ng/mL 及 0.15 ~ 20 ng/mL 之間，再藉由 Inter?day 和 Intra?day 的測試精密度，相對標準偏差 (RSD) 皆小於16 %，說明此方法有良好的再現性。最後在茶湯中也成功測出茶中含 BTHs 的存在。 ;In this study, a sensitive, simple and environmental?friendly method for the determination of eight Benzotriazoles (BTRs) and Benzothiazoles (BTHs) derivatives in tea beverages was developed. The target analytes were extracted from tea beverages using deep eutectic solvent?based ultrasound?assisted liquid?liquid microextraction (DES?USALLME). DESs are a group of novel “green” solvents, and the benefits of DESs include: starting materials are affordable, can be easily prepared at room temperature, have low or negligible toxicity, and can be tuned for hydrophobic or hydrophilic organic analytes. A hydrophobic DES was used in this study, which based on the mixture of choline chloride (as a hydrogen bond acceptor) and 4?chlorophenol (as a hydrogen bond donor) at molar ratio of 1 : 3. The determination of target analytes was performed by the combination of ultrahigh? performance liquid chromatography quadrupole time?of?flight mass spectrometry (UHPLC?QTOF?MS). The parameters of DES?USALLME were screened and optimized by multivariate experimental design base on Multilevel categoric design and Face-centered Central Composite Design plus with response surface design and analysis of variance (ANOVA), respectively. For Multilevel categoric design screening, the optimal selections were: molar ratio of DES was 1 : 3, the extraction mechanical force was ultrasonication, and no required ice bath after ultrasonication. Then, the optimal conditions for Face-centered Central Composite Design were: 800 μL of DES, and sonicated for 5 mins in ultrasonic bath at 55 ℃. After optimization, the method was validated and shown to possess low limits of quantification (LOQs) ranging from 0.15 to 20 ng/mL, high precisions (less than 16%) for both inter-day and intra-day analysis. The developed method was then successfully applied for the analysis of some selected BTRs and BTHs in tea beverages.
