HPLC法同步测定谷物中的吡虫啉和辛硫磷

建立了高效液相色谱法(HPLC)同步测定大米、荞麦、玉米等谷物中吡虫啉与辛硫磷残留量的方法.样品用乙腈提取经硅镁型吸附剂净化,以w(乙腈):w(水)=80:20作为流动相,高效液相色谱(配紫外检测器-UVD)分析,检测波长为280 nm.结果表明:该方法对谷物中吡虫啉与辛硫磷的检出限(LOD)分别为0.01 mg·kg和0.02 mg·kg,均符合相关要求; 标准品浓度在0.05～5.00 μg·mL之间时线性关系良好,相关系数分别为0.999 6和0.999 8.在0.10,0.20,0.40 mg·kg的3个水平浓度下回收率范围为81.3%～96.7%,相对标准偏差(RSD)为0.9%～4.7%.该方法具有简单、快捷、准确等优点,适合谷物中吡虫啉与辛硫磷的同步测定.

The Determination of Imidacloprid and Phoxim Residues in Cereals by HPLC

An efficient method with high performance liquid chromatography(HPLC)was established to detect the imidaclorprid and phoxim redidues in cereals(rice,buckwheat,corn,etc).The samples were extracted by methyl cyanide and prurified by florisil.Using methyl cyanide and water as mobile phase,samples were analysed by HPLC with UVD,detection wavelength of 280 nm.Test results using the methond applied in imidacloprid and phoxime can be described as follows:imidacloprid limit of detection(LOD)was 0.01 mg·kg, phoxime LOD was 0.02 mg·kg.There is a good linear relationship when the concentration is in the range of 0.05～5.00 μg·mL,the correlation coefficient of 0.999 6 and 0.999 8.The recoveries fluctuated in the range of 81.3%～96.7% for different levels(0.10,0.20,0.40 mg·kg),the relative standard deviations(RSD)were 0.9%～4.7%.Simplicity,efficiency and accuracy are the key qualities of this method which is suitable for determination of imidacloprid and phoxim residues in cereals.