| 摘要: | 防曬乳成分是一種廣泛運用在防曬乳、化妝品以及保養品的化合物。本實驗所選擇的水楊酸脂類與二苯甲酮類防曬乳成分為目前最被關切的防曬乳成分，許多研究指出，這類化合物不論在淡水、海水、底泥甚至是人類的尿液中都已被檢測出，實驗結果顯示這些化合物廣佈在環境中並且已進入食物鏈中。 本實驗利用固相萃取法結合可靠、高靈敏度且較環保的注射埠線上矽烷化衍生法，搭配氣相層析串聯式質譜儀來檢測三種防曬乳成分(EHS、HMS及BP-3)和兩種與BP-3結構類似的羥基化二苯甲酮(BP-1與BP-8)在水樣中的濃度。 本研究探討幾個影響矽烷化衍生過程的參數(如注射埠溫度、衍生化的時間以及衍生化試劑的體積等)，並作最佳化探討。最佳化的條件是將1 µL的MSTFA矽烷化衍生試劑加入10 µL經前處理所得的萃取液中，在注射埠溫度70 ?C下進行衍生化，可以得到相當好的矽烷化衍生效果。 在5-500 ?g/L的濃度範圍所做的檢量線，得到的迴歸係數皆大於0.993；此外也探討固相萃取法的條件(如使用的管柱及有機沖提液的種類等)。以HLB萃取管柱對添加待測物的水樣作萃取，得到的回收率介於62-107 %之間，其相對標準偏差都在11 %以內，顯示相當好的再現性。使用100 mL的水樣，所得到的定量極限(Limit of Quantification，簡稱LOQ)的範圍在1.0-3.0 ng/L之間。水樣中偵測到這些防曬乳成分的殘留濃度範圍介於0.5-13.4 ng/L。 本研究所發展的固相萃取法結合注射埠衍生法搭配氣相層析串聯式質譜儀，具有穩定與高靈敏度的檢測結果，提供了一個相當方便且簡單的方法來檢測環境水樣中的防曬乳成分。 UV filters are a group of chemicals used widely in sunscreen, cosmetic and skin care products. The occurrence of salicylate and benzophenone type UV filters, a group of the most concern UV filters currently, has been reported in freshwater, seawater, sediment and even in human urine suggesting that they are widespread contaminants in the environment and in food chain. Coupled with solid-phase extraction, a reliable, sensitive and eco-friendly injection-port trimethylsilylated (TMS) derivatization and gas chromatography- tandem mass spectrometry (GC?MS/MS) method was developed and applied for the first time to determine three UV filters: ethylhexyl salicylate (EHS), 3,3,5-trimethylcyclohexyl salicylate (Homosalate, HMS), 2-hydroxy-4- methoxybenzophenone (BP-3) and two related hydroxylated benzophenones (2,4-dihydroxybenzophenone, BP-1 and2,2-dihydroxy-4-methoxybenzophenone, BP-8) in water samples. The effects of several parameters related to the TMS-derivatization process (i.e., injection-port temperature, residence time and volume of silylating agent) were investigated. Addition of a solution (1 ?L) of N-methyltrimethylsilyl trifluoroacetamide (MSTFA) reagent to a 10-?L extract from the water sample gave an excellent yield of the TMS-derivatives of analytes at an injection-port temperature of 70 ?C. The linearities of analytes were achieved in the range of 5-500 ?g/L with coefficients of determination (r2) exceeded 0.993. In addition, the conditions of SPE (including the type of SPE cartridges, the elution organic solvents) were also studied. The recoveries from spiked samples ? after HLB-SPE ? ranged 62 to 107 %. Good reproducibility was obtained with relative standard deviation less than 11%. The limits of quantitation ranged from 1.0 ng/L to 3.0 ng/L (S/N= 10) in 100 mL of water samples. The total concentrations of these UV filter residues in water samples ranged from 9.4 to 17 ng/L. The analytical procedure developed demonstrated that the SPE coupled injection-port derivatization with GC-MS/MS methods are reliable, sensitive and offer a convenient analytical technique for trace determination of selected UV filters in water samples. |
