| dc.description.abstract | 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.
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