气相色谱法测定柑橘中螺螨酯残留量

目的建立气相色谱-电子捕获检测器法(GC-ECD)测定柑橘中螺螨酯残留量的方法。方法试样以乙腈为提取溶剂,经涡旋提取高速离心后氮吹浓缩定容,最后使用气相色谱电子捕获检测器测定。结果螺螨酯在0.01~2.0 mg/L浓度范围内呈现良好线性关系,R~2大于0.99,在0.1、0.5、1.0 mg/kg三个添加浓度上回收率范围为91%~106.67%,相对标准偏差小于5%,方法检出限(LOD)(S/N=3)为0.05 mg/kg,方法定量限(LOQ)(S/N=10)为0.10 mg/kg。结论该方法前处理操作简单快速,重复性好且灵敏度高,满足国内外对柑橘中螺螨酯快速、准确检测的要求,可应用于大量样品的定性定量分析。

Determination of spirodiclofen in oranges by gas chromatography

Objective To establish a method for the determination of spirodiclofen residues in orange by gas chromatography with ECD detector(GC-ECD). Methods Samples were extracted with acetonitrile. After high speed centrifugation and concentrated by nitrogen flushing, samples were detected by GC-ECD. Results The method showed a good linearity in the range of 0.01~2.0 mg/L for spirodiclofen with R2 >0.99. The recoveries were in the range of 91%~106.67% at three spiked levels of 0.1, 0.5, and 1.0 mg/kg for spirodiclofen, and the relative standard deviations (RSDs) were less than5%. Value of detection limit (S/N=3) of the method was 0.05 mg/kg, and the limit of quantification (S/N=10) was 0.10 mg/kg. Conclusion The method is suitable for quantitative and qualitative analysis of spirodiclofen in a sufficient number of orange samples with sensitivity and repeatability, which can meet the fast and accurate detection requirements of spirodiclofen residues testing at home and abroad.