气相色谱/三重四极杆串联质谱法测定牛奶及奶粉中213种农药多残留

在系统优化固相萃取吸附剂填料类型、洗脱溶剂种类及体积的基础上,建立了牛奶和奶粉中213种农药残留的气相色谱-三重四极杆串联质谱(GC-MS/MS)方法。试样用乙腈均质提取,采用石墨化炭黑/氨基柱(ENVI-Carb/NH₂)净化后,用GC-MS/MS多反应离子监测(MRM)模式进行检测,外标法定量。结果表明,197种农药在10~1000 μ g/L,16种农药在50~1000 μ g/L范围内线性关系良好,相关系数均大于0.99,方法的检出限(S/N=3)为0.03~7.59 μ g/kg,定量限(S/N=10)为0.10~21.94 μ g/kg,平均添加回收率为66.9%~120.1%,相对标准偏差(RSD)为1.23%~17.6%。该方法样品处理简单快速,相比其他多残留分析方法净化效果好,灵敏度和选择性高,适用于日常检测工作。

Determination of 213 pesticide residues in milk and milk power by gas chromatography-triple quadrupole tandem mass spectrometry

On the basis of the optimization of solid phase extraction adsorbent, eluting solvent types and amounts, a gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS) method was established for the determination of 213 pesticide residues in milk and milk power. The samples were extracted by acetonitrile, cleaned-up with an ENVI-Carb/NH₂ solid-phase extractant, and determined by GC-MS/MS using external standard method. The linear ranges were from 10 to 1000 μ g/L for 197 pesticides, from 50 to 1000 μ g/L for the other 16 pesticides with the correlation coefficients higher than 0.99. The limits of detection (LODs, S/N=3) varied over the range of 0.03 to 7.59 μ g/kg, and limits of quantification (LOQs, S/N=10) ranged from 0.10 to 21.94 μ g/kg. The average recoveries in different matrices were in the range of 66.9%-120.1% with the relative standard deviations (RSDs) of 1.23%-17.6%. This method is simple, rapid, sensitive and reliable for meeting the requirements for the simultaneous identification and quantification of the multi-residues in milk and milk power.