改良QuEChERS-超高效液相色谱-串联质谱法测定水果蔬菜中36种农药残留

Determination of 36 Pesticide Residues in Fruits and Vegetables by QuEChERS-Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry

[目的]建立QuEChERS净化-超高效液相色谱-三重四级杆串联质谱法同时测定水果及蔬菜中36种农药残留量的方法。[方法]样品前处理采用改良的QuEChERS方法,采用乙腈作为提取溶剂,经盐析分层后,取2.0 mL上清液,加入400 mg无水硫酸镁(MgSO_(4))、50 mg乙二胺-N-丙基硅烷(PSA)、50 mg十八烷基硅烷键合硅胶(C_(18))和100 mg石墨化碳黑(GCB)净化后,在多反应监测模式(MRM)下分析检测,采用Waters Atlantis T_(3)C_(18)柱(2.1 mm×150 mm,5μm)作为分析柱,梯度洗脱,外标法定量。[结果]36种农药在质量浓度为5.00~200.38 ng/mL线性关系良好(r≥0.9910),方法检出限为0.002~0.003 mg/kg,定量限为0.005~0.010 mg/kg;分别向复合果蔬汁样品中添加浓度为2倍、5倍、10倍定量限浓度的36种农药标准品,其平均加标回收率为81.70%~117.38%,仪器精密度RSD为1.10%~4.19%。[结论]建立的方法具有前处理简便、灵敏度高、准确性好、重复性强等优势,能广泛应用于不同的水果及蔬菜中农药残留的分析检测。

[Objective]To establish a method for simultaneous determination of 36 pesticide residues in fruits and vegetables by QuEChERS purification-ultra high performance liquid chromatography-triple quadrupole tandem mass spectrometry.[Method]The sample preparation was treated using the modified QuEChERS method with acetonitrile as the extraction solvent,and after salting out stratification,take 2.0 mL supernatant,purified with 400 mg anhydrous magnesium sulfate(MgSO_(4)),50 mg ethylenediamine-N-propylsilane(PSA),50 mg octadecylsilane bonded silica gel(C_(18))and 100 mg of graphitized carbon black(GCB),analyze and detect under multiple reaction monitoring mode(MRM)using Waters Atlantis T_(3)C_(18)column(2.1 mm×150 mm,5μm)as an analytical column,gradient elution and quantification using external standard method.[Result]36 pesticides had a good linear relationship(r≥0.9910)at a mass concentration of 5.00-200.38 ng/mL,with the detection limit of 0.002-0.003 mg/kg and the quantification limit of 0.005-0.010 mg/kg.36 pesticide standards with concentrations of 2 times,5 times and 10 times the quantification limit were added to the composite fruit and vegetable juice samples,the average recovery rate was 81.70%-117.38%,and the instrument precision RSD was 1.10%-4.19%.[Conclusion]The established method has the advantages of simple pretreatment,high sensitivity,good accuracy and strong repeatability,and can be widely used in the analysis and detection of a variety of pesticide residues in fruits and vegetables.