A QuEChERS sample preparation coupled with GC-MS was established for the simultaneous determination of diethylstilbestrol and estradiol residue in fish and shrimp.The QuEChERS(Quick,Easy,Cheap,Effective,Rugged and Safe) method was used for sample preparation.The sample was extracted with ethyl acetate as extraction solvent and MgSO4 as the sorbent,cleaned up by alumina-N,and then dried using a stream of nitrogen gas,derivatized with N,O-bis(trimethylsilyl) trifluoroacetamide(BSTFA) and trimethylchlorosilane(TMCS)(99∶1),and finally determined by EI-SIM-MS.The estradiol and diethylstilbestrol were quantitatively analyzed by the internal standard method,using estradiol-D2 and diethylstilbestrol-D8 as the quantitative internal standard,respectively.Good linearities were obtained in the ranges of 1-500 μg/L for diethylstilbestrol and 1-250 μg/L for estradiol,with correlation coeffcients not less than 0.999 1.The average recoveries of diethylstilbestrol and estradiol in the grass carp and shrimp at three spiked levels of 1.5,2.5,5.0 μg/kg ranged from 86.1%to 115%,with relative standard deviations(RSD) of 0.43%-7.8%.The limits of detection(LOD,S/N≥3) for diethylstilbestrol and estradiol were 0.3 μg/kg and 0.5 μg/kg,respectively.This ensures a reliable determination at levels lower than the National Minimum Required Performance Limits(2-50 μg/kg for the xenohormones) of EU and the U.S.residue limits for veterinary drugs(0.12-3 μg/kg for natural hormones).The method was simple, sensitive,rapid and accurate,and could be successfully used for the routine analysis of diethylstilbestrol and estradiol in fish and shrimp.
关键词
气相色谱-质谱(GC-MS)QuEChERS己烯雌酚雌二醇鱼虾
Keywords
GC-MSQuEChERSdiethylstilbestrolestradiolfish and shrimp