QuEChERS-同位素稀释-超高效液相色谱串联质谱法同时测定植物性食品中灭蝇胺等8种农药残留的方法研究

Study on QuEChERS isotope dilution ultra-high performance liquid chromatography-tandem mass spectrometry for simultaneous determination of eight pesticide residues'including cyromazine'in plant food

目的建立QuEChERS-同位素稀释-超高效液相色谱串联质谱法同时测定植物性食品中灭蝇胺等8种农药残留的分析方法。方法样品称量后,加入混合同位素内标,经乙腈提取,加入氯化钠和无水硫酸钠,离心后上清液经乙二胺-N-丙基硅烷化硅胶(PSA)净化,超高效液相色谱串联质谱法测定,内标法定量。结果8种农药在0.5~100μg/L浓度范围内相关系数为0.9922~0.9998,检出限为0.0001~0.002 mg/kg,定量限为0.0003~0.007 mg/kg。分别添加0.002、0.02、0.12 mg/kg 3个加标浓度后,本方法平均回收率为86.5%~110.0%,相对标准偏差为1.40%~9.80%。应用本方法检测30份市售水果和蔬菜样品,8种农药均有检出,检出率为3.33%~33.33%,均未超标,部分样品存在多种农药混合残留的现象。结论本方法可有效避免不同样品基质效应带来的干扰,准确度、精密度和灵敏度均符合检测标准要求,具有简单、稳定、可靠、易操作等特点,适用于批量样品的检测工作。

Objective To establish a QuEChERS isotope dilution ultra-high performance liquid chromatography-tandem mass spectrometry method for simultaneously determining eight pesticide residues,including cyromazine,in plant-based foods.Methods After weighing the sample,a mixed isotope internal standard was added,extracted by acetonitrile,sodium chloride and anhydrous sodium sulfate were added.After centrifugation,the supernatant was purified by ethylenediamine-Npropylsilanized silica gel(PSA),and determined by ultra-high performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS),and quantified by internal standard method.Results The correlation coefficients of eight pesticides within the concentration range of 0.5~100μg/L were 0.9922 to 0.9998,the detection limit was 0.0001 to 0.002 mg/kg,and the quantitative limit was 0.0003 to 0.007 mg/kg.After adding three spiked concentrations of 0.002,0.02,and 0.12 mg/kg,the average recovery rate of this method was 86.5%to 110.0%with the relative standard deviation of 1.40%to 9.80%.This method was applied to detect 30 samples of commercially available fruits and vegetables,and all eight pesticides were detected,with detection rates of 3.33%to 33.33%,all of which did not exceed the standard.Some samples showed mixed residues of multiple pesticides.Conclusion This method can effectively avoid interference caused by matrix effects of different samples,and its accuracy,precision,and sensitivity all meet the requirements of detection standards.It has the characteristics of simplicity,stability,reliability,and ease of operation,and is suitable for the detection of batch samples.