谷虫净在仓储原粮中的残留消解动态与安全性评价

Studies on residue analysis and degradation of Deltamethrin in rice and rice bran

采用气相色谱分析谷虫净(溴氰菊酯)在原粮中的残留量,样品经石油醚/乙醚混合液提取,乙腈分配,正已烷萃取,层析柱净化,色谱定量。方法准确度:糙米88 0%～91 4%,米糠95 7%～97 5%;标准偏差:糙米1 01～1 71,米糠1 46～1 69;变异系数:糙米1 10%～1 94%,米糠1 53%～1 75%;最小检出量3 8×10-12g,最小检出浓度0 002mg/kg。无论是高剂量(药∶粮=3∶1000)还是低剂量(药∶粮=1 5∶1000),药后30d,糙米中残留量均<0 002mg/kg;残留消解曲线方程:广西为c=1 5566e-0 3276T,湖南为c=1 6772e-0 3019T,半衰期(T/2)=5～6d,消解90%时需30d左右。我国规定原粮中溴氰菊酯最高允许残留限量0 5mg/kg,根据本试验结果,推荐试药剂量,药∶粮=1 5∶1000,安全间隔期30d,是安全的。

Residual deltamethrin in rice and rice bran were extracted by petroleum ether/aether mixture and n-Hexane,parted by Acetonitrile,cleaned up by passing through a magnesium silicate column,and determined by GC.The results showed that the degree of accuracy were respectively 88.0%-91.4% in rice and 95.7%-97.5% in rice bran.The standard deviation were respectively 1.01-1.71 in rice and 1.46-1.69 in rice bran.The coefficient of variation were respectively 1.10%-1.94% in rice and 1.53%-1.75% in rice bran.The minimum detectable amount and minimum detectable concentration were 3