高效液相色谱法测定茶叶中的5种农药残留

建立高效液相色谱法检测茶叶样品中5种农药残留分析方法,以期为茶叶绿色生产提供技术理论支撑。样品经水浸泡后,用正己烷和丙酮混合液(V:V=5:1)振荡提取,乙酸乙酯萃取,经弗罗里硅土和活性炭层析柱净化后,高效液相色谱检测茶叶中5种农药（高效氯氟氰菊酯、氯氰菊酯、联苯菊酯、噻虫嗪和吡虫啉）残留量。结果表明：在0.1~10.0 mg/L范围内,5种农药的色谱峰面积与其浓度均呈良好的线性关系,相关系数均大于0.9994,在0.1、0.5、1 mg/L的添加水平下,5种农药在空白茶叶样品中的平均回收率均在85%~95%之间,相对标准偏差(RSD)在0.55%~2.5%之间。该方法符合农药残留分析实验要求,灵敏度高。

Determination of 5 Kinds of Pesticide Residues in Tea by HPLC

To provide technical support for green tea production, HPLC method for determining 5 kinds of pesticide residues in tea samples was established. After soaking in water, the samples were extracted by V (n-hexane): V(acetone)=5:1, then extracted by ethylacetate, purified by floriferous silica and activated carbon column. High performance liquid chromatography (HPLC) was used to determine the pesticides of lambda-cyhalothrin, cypermethrin, bifenthrin, thiamethoxam and imidacloprid in the samples. The results showed that there was a good linear relationship between the chromatographic peak area and the concentration of the 5 pesticides in the range of 0.1-10.0 mg/L. The correlation coefficients were higher than 0.9994. The average recovery rate at three spiked levels of 0.1, 0.5 and 1 mg/L ranged from 85% to 95%, with the relative standard deviation (RSDs) from 0.55% to 2.5% in the blank tea samples. The method could meet the requirements of pesticide residue analysis test and has a high sensitivity.