蔬菜农药残留检测中的基质效应对检测结果的影响

Influence of Matrix Effect on Pesticide Residues Detection in Vegetables

为了提高蔬菜农药残留检测结果的准确性,采用相同浓度的基质标准工作液与溶剂标准工作液的峰面积的相对比值来评价基质效应。研究了8种蔬菜对16种农药残留的基质效应,结果表明:绝大多数农药在蔬菜基质中表现出增强基质效应,会造成检测结果偏高,其中韭菜基质对所有农药都呈现出强基质效应,即ME>1.5;其对三唑磷的基质增强效应明显,数值在7.56~10.72;0.05mg/kg的甲拌磷在油菜、黄瓜、马铃薯基质中表现出中等减弱基质效应,会造成检测结果偏低;三唑酮在油菜、黄瓜、辣椒等蔬菜基质,以及甲拌磷、毒死蜱、联苯菊酯在番茄等蔬菜基质中均呈现弱基质效应,造成检测结果偏差小。极显著强基质效应由强到弱的蔬菜品种依次为:韭菜>芹菜>莲藕>马铃薯>黄瓜>辣椒>油菜>番茄。此外,采用基质标准溶液比采用试剂标准溶液计算的加标回收率更加趋向符合标准要求的范围内,农药残留加标回收率的符合标准要求占比均有大幅度提高,其中番茄、马铃薯的农药残留回收率的符合标准要求占比达100%。这表明采用基质标准溶液计算可以有效降低蔬菜基质效应对农药残留检测结果的影响,提高检测结果的准确性。

To improve accuracy of pesticide residue detection of vegetable,the relative ratio of peak areas of matrix standard working solution and solvent standard working solution of the same concentration was used to evaluate the matrix effect.The matrix effect of 8 vegetables on 16 pesticide residues was studied,and the results showed that the vast majority of pesticide showed matrix effect in vegetable matrices,leading to higher detection results.The leek matrices showed a strong matrix effect on all pesticides,with ME>1.5;and a significant matrix-enhanced effect on triazophos,with ME ranging from 7.56 to 10.72;0.05 mg/kg of phorate showed a moderately weakened matrix effect in rape,cucumber,and potato matrices,leading to lower detection results;triadimefon showed a weak matrix effect in vegetable matrices such as rape,cucumber and pepper,and so did phorate,chlorpyrifos and bifenthrin in vegetable matrices such as tomato,leading to small deviation of detection results.The vegetables with extremely significant strong matrix effects ranging from strong to weak were:leek>celery>lotus root>potato>cucumber>pepper>rape>tomato.Moreover,recovery calculated with matrix standard solution was more in line with the standard requirements than that calculated with solvent standard solution,and proportion of pesticide residue reco-very meeting the standard requirements had greatly increased,among which the proportion of pesticide residue recovery meeting the standard requirements of tomatoes and potatoes had reached 100%.This showed that calculating with matrix standard solution can effectively reduce the influence of vegetable matrix effect on pesticide residue detection and improve the accuracy of detection results.