OPTIMIZATION OF SOXTEC EXTRACTION PROCEDURE FOR DETERMINATION OF POLYBROMINATED DIPHENYL ETHERSIN BIVALVE MOLLUSC

摘要

A comprehensive and efficient method is presented forthe determination of 9 polybrominated dipheny! ethercon-geners (PBDEs), 2,4,4'-tribromodiphenyl ether (PBDE-28), 2,3',4,4'-tetrabromodiphenyl ether (PBDE-47), 2,2',4,4',6-pentabromodiphenyl ether (PBDE-66), 2,2',4,4',5-pentabromodiphenyl ether (PBDE-100), 2,2',3,4,4'-pentabromodiphenyl ether (PBDE-99), 2,2',4,4',5,6'-hexabromodiphenyl ether (PBDE-85), 2,2',4,4',5,5'-hexabromodiphenyl ether (PBDE-154), 2,2',4,4',5,5'-hexabromodiphenyl ether (PBDE-153) and 2,2',3,4,4',5,6'-heptabromodiphenyl ether (PBDE-183), in mollusc bivalve samples. An experimental design was used to evaluate the influence of several operational parameters on the extraction performance and to obtain the best experimental conditions. Under the final working conditions, freeze-dried mollusc was placed in the Soxtec thimble in order to extract PBDEs with 100mLof/2-hexane—acetone(4: l)after 1.5 and 1 h of boiling and rinsing times, respectively. Soxtec extracts were additionally purified on a multilayered column and after injected in the gas chromatography combined with mass spectrometry (GC—MS) system. Quantitative recoveries of the analytes at three concentration levels ranged between 80 and 108%, and limits of quantificationof the method (LOQs) between 0.5 and 20 ng/g. Analysis of mussel and clam samples showed that PBDE-47 and PBDE-99 were presented in almost all samples with concentrations between 0.6 and 2.6 ng/gdry weight. Moreover, a certified reference material (NIST2974a) was used. The obtained concentrations were in agreement with the certified values.