三重四极杆气相色谱质谱联用法测定茶叶中31种农药残留

目的 建立一种简便、快速、安全、价格低廉的三重四级杆气相色谱质谱联用仪法(QuEChERS-GC-MS/MS)测定茶叶中的31种农药残留的分析方法。方法 以0.5%的乙酸-乙腈(v/v)溶液作为溶剂,以加入无水硫酸镁、醋酸钠进行浸提,浸提后用硅酸镁、乙二胺-N-丙基硅烷化硅胶(PSA)、C18和石墨化炭黑(GCB)净化试剂净化,净化液用氮吹仪浓缩至干,用0.5%的乙酸-乙腈定容至,采用内标法定量,气相色谱-质谱联用仪(GC-MS/MS)同时测定31种农药残留。结果 31中农药的线性相关系数达到0.999以上,检测限(LOD)为0.01~0.05mg/kg。同时采用红茶和绿茶作为基质本底, 用加标回收评价了该方法的精密度和重现性,31种农药的平均回收率为85%-105%,相对标准偏差为0%-10%。结论 该方法操作简便快捷、检测成本低,方法的灵敏度、准确度和精密度符合茶叶中农药残留测定的技术要求。 关键词: QuEChERS; 三重四级杆气相色谱质谱联用仪; 农药残留; 茶叶

Determination of 31 kinds of pesticide residues in tea by triple quadrupole gas chromatography-mass spectrometry

Objective To establish a simple, rapid, safe and inexpensive method for the determination of 31 pesticide residues in tea by triple quadrupole gas chromatography-mass spectrometry (quechers-gc-ms / MS). methods 0.5% acetic acid acetonitrile (V / V) solution was used as solvent, anhydrous magnesium sulfate and sodium acetate were added for extraction. After extraction, magnesium silicate, ethylenediamine-n-propylsilylated silica gel (PSA), C18 and graphitized carbon black (GCB) purification reagents were used for purification. The purification solution was concentrated to dryness by nitrogen blowing instrument, and then diluted to volume by 0.5% acetic acid acetonitrile. The internal standard method was used for quantification, and gas chromatography-mass spectrometry was used (GC-MS / MS) simultaneous determination of 31 pesticide residues. Results The linear correlation coefficient of 31 pesticides was above 0.999, and the limit of detection (LOD) was 0.01 ~ 0.05mg/kg. The average recoveries of 31 pesticides were 85% - 105%, and the relative standard deviations were 0% - 10%. Conclusion The sensitivity, accuracy and precision of the method meet the technical requirements for the determination of pesticide residues in tea.