Optimisation of matrix solid-phase dispersion for the determination of Dechlorane compounds in marketed fish

A method for the determination of chlorinated flame retardants: Dechlorane Plus, Dechlorane (Dec) 602, Dec 603 and Dec 604, in marketed fish is described. The method involves the use of matrix solid-phase dispersion (MSPD) prior to their determination by gas chromatography-electron-capture negative-ion chemical-ionisation mass spectrometry (GC-ECNICI-MS). Parameters that affect the extraction efficiency of the target analytes from fish samples were optimised using a Box-Behnken design method. MSPD integrated the extraction and clean-up procedures into a single step, which provides the benefits of being simple and convenient. The optimal extraction conditions involved dispersing a freeze-dried fish (1-g) in 2-g of silica gel, and packed with 1-g of Florisil, and then the target analytes were eluted with 20 mL of n-hexane. The limits of quantification were 9-15 pg/g-lipid weight. Preliminary results showed that the total concentrations of the target analytes ranged from 0.15 to 1.3 ng/g-lipid weight.