基于固相微萃取-气相色谱(SPME-GC)建立了检测茶叶中氟虫腈及其代谢物(脱亚硫酰基氟虫腈、硫化氟虫腈、氟虫腈砜、酰胺氟虫腈)残留的分析方法.实验中采用85μm聚丙烯酸酯(PA)萃取头,萃取温度为60℃,萃取缓冲体系的pH值为9.当添加水平为2～10μg/kg时,回收率在71.2%～109.3%之间,相对标准偏差(RSD)在1.2%～7.1%之间.方法的检出限(LOD)和定量限(LOQ)分别在0.3～1.2μg/kg和1.0～4.0μg/kg之间.对所建立的方法采用气相色谱-质谱(GC-MS)进行确证,结果令人满意.本方法灵敏度、精密度和LOD均符合残留分析要求,具有快速、灵敏度高的特点,适合于茶叶中氟虫腈及其代谢物残留的痕量分析.%An effective multi-residue method for the trace analysis of fipronil and four metabolites ( fipronil-desulfinyl, fipronil-sulfide , fipronil-sulfone and fipronil-carboxamide ) in tea was developed based on solid-phase microextraction coupled with gas chromatography ( SPMEGC ). The targets were extracted with a fused-silica fiber coated with 85 μm polyacrylate PA ). The extraction was performed in a pH 9 buffer ( containing 0. 1 mol/L boracic acid , 0. 1 mol/L KCI and 0.1 mol/L NaOH ) at 60℃ and under 2500 r/min for 30 min. With the concentration range of 2 - 10μg/kg, the recoveries ranged from 71.2％ t0 109.3％ and the relative standard deviations ( RSDs ) were lower than l0％ ( n = 6 ). The limits of detection ( LODs ) and limits of quantitation ( LOQs ) of the studied compounds ranged from 0. 3μg/kg t0 1.2μg/kg and 1.0 μg/kg t0 4. 0μg/kg, respectively , with the values well below the residue limits set by Japan, European Union and China. By the proposed method, 1 positive samples of 30 tea samples were found with fipronil and fipronil-sulfone. The identification of the method was done by gas chromatography-mass spectrometry ( GC-MS ). The method can be applied as a monitoring tool for tea, in the investigation of food to fipronil and its metabolites.
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