气相色谱-质谱法检测鳗鱼中三氯杀螨醇残留量

建立了固相萃取-气相色谱-质谱(SPE-GC-MS)检测鳗鱼中三氯杀螨醇残留量的分析方法。样品先用正己烷配合乙腈、水均质提取,再加入氯化钠继续均质,离心分层;取部分乙腈层溶液浓缩后过Florisil柱净化,用正己烷淋洗去除油脂,再用乙酸乙酯-正己烷(1:19, v/v)洗脱分析物;将洗脱液吹干后用正己烷溶解定容,并进行GC-MS分析。采用选择离子监测(SIM)模式检测,外标法定量。在优化的样品前处理条件和GC-MS条件下,方法的定量限(S/N=10)小于0.01 mg/kg;在加标水平为0.01～0.1 mg/kg时,回收率为91%～105%,相对标准偏差为4.3%～6.1%。该方法准确、灵敏、快速,可满足鳗鱼中三氯杀螨醇残留的检测要求。

Determination of dicofol residue in eel by gas chromatography-mass spectrometry

A method was developed and applied to determine the residual dicofol in eel by gas chromatography-mass spectrometry (GC-MS). The residue was extracted from homogenized tissue with acetonitrile-water assisted by n-hexane, separated with liquid-liquid partition. A part of the supernatant was purified using solid phase extraction (Florisil column) prior to the GC-MS analysis. The determination was performed in selected ion monitoring (SIM) mode with the external calibration for quantitative analysis. Under the optimized conditions, the quantification limit of the method (S/N=10) was lower than 0.01 mg/kg. The recovery of the method for the spiked standard at the concentration of 0.01~0.1 mg/kg was 91%~105% with the relative standard deviation (RSD) of 4.3%~6.1%. The method is easy, fast, and more sensitive. The method can meet the requirement of the determination of dicofol in eel.