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).