快速溶剂萃取-气相色谱质谱法快速测定茶叶中7种拟除虫菊酯农残

摘要

The samples were extracted with hexane/acetone (80:20,v/v),the extracts were dried with water bath,then the analytes were dissolved with 2 mL hexane,1 mL of the dissolved analytes were purified by dispersed solid phase extraction (DSPE).Finally,the target analytes were detected by tandem mass spectrometry.The results showed that good linearity was obtained in the ranged of 0.02-1μg/g for the seven pyrethroids with correlation cofficients better than 0.9993.The limits of detection were in range of 0.5-15ng/g (S/N=3) and the limits of quantitation were in range of 2 -40ng/g (S/N=10).The recoveries of the method were in range of 84.3% -102.9% at the spiked levels of 0.1-0.5μg/g (0.1,0.25,0.5μg/g) for all analytes,with the relative standdard deviations less than 5.5%.The method is very applicable in daily tea analysis.%建立了快速溶剂萃取(APLE)-气相色谱质谱法(GC-MS)测定茶叶中7种拟除虫菊酯农药残留的方法,并对影响APLE萃取效果的因素进行了考察.样品经正己烷/丙酮(80:20,v/v)提取,提取液水浴蒸干后用2mL正己烷复溶,取出1mL复溶液于样品管中进行分散固相萃取(dSPE)净化操作,最后用GC-MS检测.7种拟除虫菊酯在0.02~1μg/g范围内呈现良好的线性关系,线性相关系数≥0.9993.检出限为0.5~15 ng/g(S/N=3),定量限为2~40 ng/g(S/N=10);添加水平为0.1~0.5μg/g(0.1、0.25、0.5μg/g)时,方法的回收率为84.3~102.9%,精密度≤5.5%.该方法自动化程度高,萃取效率高,精密度好,分析快速,适合茶叶中拟除虫菊酯类农药残留的日常检测工作.