气相色谱法测定茶叶中有机氯和拟虫菊酯类农药残留的基质效应
目的 探究气相色谱法测定茶叶基质中17种有机氯和拟虫菊酯类农药残留的基质效应。方法 应用QuEChERS法快速处理茶叶样品得到基质溶液, 用基质溶液配制3个不同浓度的混合标液, 用气相色谱法进行测定, 其结果与正己烷溶剂配制的相同浓度混合标液进行比较。结果 不同种农药在茶叶基质中的基质效应普遍存在, 随着质量浓度的减小, 基质效应的影响程度会增大; 大部分表现为基质增强效应, 0.004 mg/L的浓度下有10种农药, 强度最大的是百菌清, 基质效应为156.9%~360.7%; 也有一部分表现为基质抑制效应, 0.004 mg/L的浓度下有7种农药, 强度最大的是三氯杀螨醇, 基质效应为24.5%~46.6%; 在不同的茶叶基质中同种农药的基质效应程度差别不大, 6种不同茶叶基质的农药基质效应的标准偏差基本都在10%以内; 在相同的茶叶基质中有机氯农药比菊酯类农药的基质效应更强。结论 由于基质效应普遍存在, 在较低浓度下基质效应比较显著, 因此在日常的茶叶农残检测时, 为了得到更准确的数据, 应当采用基质标准曲线进行定量分析。
Objective To explore the matrix effects of 17 kinds of organochlorine and pyrethroid pesticides residues in tea matrix by gas chromatography. Methods The matrix solution was obtained by rapid processing of tea samples using the QuEChERS method, the 3 mixed standard solutions of different concentrations were prepared with the matrix solution and measured by gas chromatography. The results were compared with the mixed standard solutions of the same concentration prepared with n-hexane solvent. Results The matrix effects of different kinds of pesticides in the tea matrix were widespread, and the influence degree of the matrix effect increased with the decrease of mass concentration. Most of them showed matrix enhancement effect. There were 10 kinds of pesticides at a concentration of 0.004 mg/L, the strongest was chlorothalonide, and the matrix effects were 156.9%?360.7%. A part of them also showed matrix inhibitory effect. There were 7 kinds of pesticides at a concentration of 0.004 mg/L, the most powerful was dicofol, and the matrix effects were 24.5%?46.6%. There was little difference in the degree of matrix effect of the same pesticide in different tea matrices. The standard deviations of the pesticide matrix effects of the six different tea matrices were basically within 10%. Organochlorine pesticides had a stronger matrix effect than pyrethroid pesticides in the same tea matrix. Conclusions Since the matrix effect is widespread, and the matrix effect is more significant at lower concentrations. Therefore, standard matrix curve should be used for quantitative analysis in daily tea residue testing in order to obtain more accurate data.
标题：气相色谱法测定茶叶中有机氯和拟虫菊酯类农药残留的基质效应
英文标题：Matrix effects of the determination of organochlorine and pyrethroid pesticide residues in tea by gas chromatography
作者：
杨延峰 清远市食品检验中心
袁晓丽 清远市食品检验中心
中文关键词:茶叶,气相色谱法,农药残留,基质效应,
英文关键词:tea,gas chromatography,pesticide residue,matrix effect,
发表日期：2020-07-30
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