固相萃取-气相色谱-串联质谱法测定大米中10种除草剂

Determination of 10 herbicides in rice by solid-phase extraction-gas chromatography-tandem mass spectrometry method

目的建立固相萃取-气相色谱-串联质谱法同时测定大米中10种除草剂残留的方法。方法采用乙腈漩涡提取样品中待测组分,通过比较Carbon/NH2柱、Florisil柱、HLB柱、PSA柱4种小柱对大米中10种除草剂的吸附和净化情况,选Carbon/NH2柱进行净化,大米对10种除草剂均存在基质加强效应,以大米基质校准工作曲线,采用气相色谱-串联质谱法在多反应监测(MRM)模式下进行测定,外标法定量。结果 10种除草剂的质量浓度为40μg/L^1 600μg/L时,线性关系良好,相对标准偏差(RSD)<10%,加标回收率为76.9%~109.5%。按信噪比(S/N)为10计,本方法的检出限(LOQ)为0.09μg/kg^1.2μg/kg。结论该分析方法背景干扰低、灵敏度高、检出限低于国家标准及相关文献报道值,适合大米中除草剂的同时测定。

Objective To develop a method for the determination of 10 herbicides in rice by gas chromatography coupled tandem mass spectrometry after solid phase extraction（ SPE）. Methods The components in the sample were extracted with acetonitrile vortex. By comparing the adsorption and purification of Carbon / NH2 column,Florisil column,HLB column and PSA column four column to 10 herbicides in rice,Carbon / NH2 column was chosen to purified. The effect of matrix enhancement was found in 10 herbicides in Rice. The determination was conducted by by GC- MS / MS in the multiple reaction monitoring（ MRM） mode. The quantity was determined by external standard method. Results The mass concentration of the 10 herbicides was among 40 μg / L- 1 600 μg / L,and the linear relationship was good with the relative standard deviation（ RSD） 10%,and the standard recovery rate was among 76. 9%- 109. 5%. According to the signal to noise ratio（ S / N） of 10,the detection limit of the method（ LOQ） was among 0. 09 μg / kg- 1. 2 μg / kg. Conclusion The analysis method has the advantages of low background interference,high sensitivity and low detection limit,which is suitable for the simultaneous determination of herbicides in rice.