Vortex-homogenized matrix solid-phase dispersion coupled with gas chromatography – electron-capture negative-ion mass spectrometry to determine halogenated phenolic compounds in seafood†
This study developed the efficacy of a method that was able to rapidly determine three halogenated phenolic compounds (HPCs, i.e., pentabromophenol (PeBP), tetrachlorobisphenol A (TCBPA) and tetrabromobisphenol A (TBBPA)) in marketed seafood samples. The method employed modified vortex-homogenized matrix solid-phase dispersion (VH-MSPD) prior to the detection of the halogenated phenolic compounds by injection-port silylation gas chromatography – electron-capture negative-ion mass spectrometry (GC-ECNI-MS), which was set to operate in the selected ion monitoring (SIM) mode. Parameters that impact the efficiency of extraction for VH-MSPD were optimized through the Box–Behnken design method. Under optimal conditions, 0.5 g of freeze-dried seafood tissue was mixed with 0.5 g of anhydrous sodium sulfate, and the treated sample was dispersed with 1.0 g of Florisil via a vortex. The blend was transferred to a glass column containing 1.0 g of octadecyl bonded silica (C18), used as clean-up co-sorbent. The target analytes were then eluted with 12 mL of acetonitrile. The concentrated extract was derivatized in the GC injection-port through reaction with silylating reagent (BSTFA), and the identity and quantity of the target analytes present in the samples were determined by the GC-ECNI-MS system. The limits of quantitation (LOQs) were 0.2 to 0.5 ng g−1 (dry weight). A preliminary result revealed that trace levels of halogenated phenolic compounds were detected in various kinds of marketed seafood samples.