摘要
为确定气相色谱法测定茶叶中拟除虫菊酯农药残留量的最佳试验条件,采用外标法定量,对样品的提取净化方法和气相色谱的测定条件进行了探讨。经试验确定的色谱条件为:起始温度180℃,最终温度270℃,并保持15 min;样品提取净化条件为:以石油醚—丙酮(V/V,3:1)为提取液,Florisil固相萃取小柱净化,用石油醚—乙酸乙酯混合溶液(V/V,9:1)进行洗脱。回收率及精密度试验表明:在0.008～0.800 mg/L浓度范围内,线性方程的线性关系良好,相关系数r≥0.997 3;回收率为80.7%～105.8%,相对标准偏差为1.8%～8.9%,最低检出限为0.000 3～0.004 2 mg/kg。此方法灵敏度高,净化效果好,重现性好。
The article is aimed at studying the method of determining and analyzing pyrethroid pesticides in tea.The pesticide residues were extracted from tea samples by petroleum ether-acetone （V/V,3： l）,and were cleaned up with the Florisil column, eluted with（V/V, 9：1 ）, then determined with gas chromatography equipped with electron-capture detector （GC-ECD）. The recoveries obtained from tea samples （n-5）added with pesticide standards at the three levels of 0.2mg/L,0.4mg/L,0.8mg/L are in the ranges of 80.7% to105.8%,with the RSDs in the ranges of 1.8% to 8.9%. The detection limits of the pyrethroids are in the range of 0.0003 to 0.0042 mg/kg
出处
《农业科技与装备》
2010年第1期19-21,共3页
Agricultural Science & Technology and Equipment
