二步净化-气相色谱-串联质谱测定茶叶中22种农药残留量

Determination of multi-pesticide residues in tea by two-step clean-up and gas chromatography-tandem mass spectrometry

中文关键词:  二步净化  茶叶  农药残留  气相色谱-串联质谱

英文关键词:two-step clean-up  tea  pesticide residues  gas chromatography-tandem mass spectrometry

中文摘要:

      目的 建立了基于多酚-钙沉淀及磁性吸附材料二步净化与气相色谱-串联质谱测定茶叶中多种农药残留的方法。方法 根据多酚类物质与金属离子尤其是钙离子的作用原理在前处理方法中引入无水氯化钙进行初步净化和除水, 后续采用磁性石墨烯与石墨化炭黑进行二次净化。对提取方式、二步净化条件进行了优化, 选择了22种有代表性的农药化合物, 验证了线性范围、检出限、定量限、精密度与回收率, 并对仅采用磁性石墨烯进行净化可行性进行了探讨。结果 所建立的方法在0～200 ng/mL浓度范围呈良好线性关系, 相关系数均大于0.995, 在0.01、0.05和0.10 mg/kg添加水平下, 平均回收率为63.03%~98.69%, 相对标准偏差为2%~21%, 检出限和定量限分别在1~10 μg/kg和5~35 μg/kg。结论 该方法操作简便、准确、快速, 适用于乌龙茶、红茶和黑茶中农药残留的分析与监控。

英文摘要:

      Objective To establish a method for determination of multi-pesticide residues in tea based on polyphenol-calcium precipitation and magnetic adsorption material two-step clean-up and gas chromatography-tandem mass spectrometry. Methods According to the principle of action of polyphenols and metal ions, especially calcium ions, anhydrous calcium chloride was introduced into the pretreatment method for preliminary clean-up and water removal, followed by secondary clean-up using magnetic graphene and graphitized carbon black. The extraction method and conditions of the two-step clean-up method were optimized, and 22 representative pesticide compounds were selected, and the linear range, detection limit, limit of quantification, precision, and recovery were verified. The feasibility of clean-up using only magnetic graphene was discussed. Results The established method had a good linear relationship in the concentration range of 0 to 200 ng/mL, and the correlation coefficients were all greater than 0.995. At the addition levels of 0.01, 0.05, and 0.10 mg/kg, the average recoveries were 63.03%-98.69%, with relative standard deviations of 2%-21%, and the range of Limits of detection and limits of quantitative were 1~ 10 μg/kg and 5~35 μg/kg, respectively. Conclusion The method is simple, accurate and fast, and suitable for the analysis and monitoring of 22 pesticide residues in oolong tea, black tea and black tea.