在线凝胶渗透色谱-气相色谱-质谱法测定茶叶中多种有机锡化合物残留

建立了茶叶中6种有机锡化合物残留的在线凝胶渗透色谱-气相色谱/质谱(GPC-GC/MS)分析方法.样品用盐酸酸化,以丙酮-正己烷为提取剂振荡提取,浓缩、干燥后加入正戊基溴化镁进行衍生,衍生产物用正己烷提取,经Envi-Carb活性碳和Florisil串联固相萃取柱净化,再经在线GPC进入GC/MS检测.当加标水平为0.01、0.05和0.10mg/kg时,回收率为66.2%～105.6%,相对标准偏差为2.7%～10.4%.方法的检出限为0.01mg/kg.实验证明,该方法快速、简便、准确、灵敏度高,可用于茶叶中有机锡化合物残留的同时检测.

Determination of 6 Organotin Compound Residues in Tea by On-line GPC-GC/MS Method

An analytical method using the on-line gel permeation chromatography- gas chromatography/mass spectrometry has been developed for the determination of 6 organotin compounds in tea.After acidified by hydrochloric acid, the sample was extracted with acetone-hexane,the crude extract was concentrated, dehydrated, and derivatized by n-pentyl magnesium bromide. Then the derivative was extracted by n-hexane and purified on a Envi-Carb and Florisil solid phase extraction column, and then analysed on an on-line gel permeation chromatographic-gas chromatographic/mass spectrometer（GPC-GC/MS）.The recoveries in the spiked sample with standards of 0.01, 0.05 and 0.10 mg/kg were 66.2%～105.6%, and the relative standard deviations were between 2.7%～10.4%.The limits of detection were 0.01 mg/kg.The method is proved to be rapid, easy, accurate, highly sensitive, and can be used for the simultaneous determination of organotin compounds in tea.