QuEChERS-气相色谱质谱法测定苹果中45种农药残留

建立了QuEChERS-气相色谱质谱法同时测定苹果中45种农药残留检测方法,样品以1%乙酸乙腈提取,经25 mg PSA、25 mg C₁₈和7.5 mg GCB净化,GC-MS选择离子监测(SIM)模式下检测,基质匹配外标法定量。检测结果表明,45种农药在10~200 μg/L质量浓度范围内线性关系良好,各农药的线性相关系数均大于0.995;在30、50和100 μg/kg添加水平下,45种农药的回收率在69.3%~116%之间,相对标准偏差在0.7%~7.9%之间;方法的检出限在1.5~15.0 μg/kg之间,定量限在5.0~50.0 μg/kg之间。该方法准确度高、精密度好、步骤简单、操作快捷、成本低廉,适用于苹果中农药残留的检测。

Determination of 45 Pesticide Residues in Apples by QuEChERS-Gas Chromatography-Mass Spectrometry

A method for the simultaneous determination of 45 pesticide residues in apple by QuEChERS-gas chromatography-mass spectrometry was established. Apple samples were extracted by acetonitrile containing 1%(V%)acetic acid,and purified by 25 mg PSA,25 mg C₁₈ and 7.5 mg GCB. And detected in GC-MS selective ion monitoring(SIM)mode,and quantitatively analyzed with the matrix-matched external standard calibration curves. Test results showed that the 45 pesticides had good linearity in the range from 10~200 μg/L,and the determination coefficients of pesticides were greater than 0.995. The average recovery ranges were mainly between 69.3% and 116% at the three spiked concentration levels(30,50,100 μg/kg),and the relative standard deviations were between 0.7% and 7.9%. The LOD(limit of detection)was from 1.5 to 15.0 μg/kg,and LOQ(the limit of quantification)was from 5.0 to 50.0 μg/kg.The method is accurate,precise,simple,fast and economic. It is suitable for the detection of pesticide residues in apples.