气相色谱-串联质谱法测定原料类果酱中百菌清残留量

建立了原料类果酱中百菌清农药残留的气相色谱-串联质谱（GC-MS/MS）测定方法。通过对关键步骤进行优化，样品经乙腈提取，氟罗里硅土固相萃取柱净化，气相色谱-串联质谱仪测定，外标法定量。结果表明：百菌清的定量限为0.01 mg/kg；标准曲线在5~250 ng/mL范围内线性良好，相关系数＞0.99；在0.01~0.1 mg/kg浓度范围的加标实验中，回收率为83.0%~111.0%，精密度为3.7%~10.3%，符合方法学验证要求。该方法操作简便，结果准确，可适用于不同种类的原料类果酱中百菌清残留的测定。

Determination of chlorothalonil residues in raw jam by gas chromatography-tandem mass spectrometry

Objective To establish a method for quantitative determination of chlorothalonil pesticide residue in raw jam materials by gas chromatography-tandem mass spectrometry (GC-MS/MS). Methods The sample was hydrated by 8 mL of deionized water, extracted by using acetonitrile, salted out with 4 g sodium chloride, centrifuged at 4200 r/min for 8 min. The supernatant was cleaned up by a florisil solid phase extraction column and eluted by n-hexane-acetone mixture (9:1, V:V), the analytes were determined by GC-MS/MS and quantified by external standard method. Results The standard curve had a good linear relationship in the range of 5?250 ng/mL, with the correlation coefficient was greater than 0.99. The limit of quantification of chlorothalonil was 0.01 mg/kg; the recoveries varied from 83.0% to 116.8% and the relative standard deviations varied from 3.7% to 10.3% at spiked levels of 0.01?0.10 mg/kg. Conclusion This method is simple, convenient, accurate and suitable for detection of chlorothalonil residue in raw jam materials.