Determination of paraben preservatives in seafood using matrix solid-phase dispersion and on-line acetylation gas chromatography−mass spectrometry

An effective method for determining four commonly detected paraben preservatives (methyl, ethyl, propyl and butyl paraben) in marketed seafood is presented. This method employs matrix solid-phase dispersion (MSPD) before identification and quantification of the paraben preservatives via on-line acetylation gas chromatography–mass spectrometry (GC–MS). Parameters affecting the extraction efficiency of MSPD were optimized through a Box-Behnken design method. Under optimal condition, 0.5-g of freeze-dried seafood was mixed with 0.5-g of anhydrous sodium sulfate, and dispersed with 1.0-g of Florisil using vortex. After that, the blend was transferred to a glass column containing 1.5-g of silica gel + C18 (w/w, 9:1), which acted as clean-up co-sorbents. Then, target analytes were eluted with 12 mL of acetonitrile. The extract was then derivatized on-line in the GC injection-port through reaction with acetic anhydride, and the identity and quantity of the target analytes were determined by the GC–MS system. The limits of quantitation (LOQs) were 0.2 to 1.0 ng/g (dry weight). Preliminary results showed that the total concentrations of four selected parabens ranged from 16.7 to 44.7 ng/g (dry weight).