凝胶渗透色谱-高效液相色谱-线性离子阱质谱法测定膳食样品中的氨基甲酸酯类农药残留

建立了高效液相色谱-线性离子阱质谱（HPLC-LIT-MS）测定膳食样品中氨基甲酸酯类农药的检测方法。样品中加入同位素内标，用正己烷饱和的乙腈超声提取，凝胶渗透色谱净化。以乙腈和含5 mmol/L甲酸铵和0.1%（v/v）甲酸的水溶液为流动相，目标化合物经CAPCELL PAK CR （100 mm×2.1 mm，5 μm；SCX-C₁₈ （1：4））色谱柱分离，梯度洗脱，流速0.2 mL/min。采用电喷雾电离，选择反应监测（SRM）正离子模式三级离子监测。内标法定量。膳食类样品中氨基甲酸酯农药的平均加标回收率在60.4%~114%之间；相对标准偏差在3.46%~16.2%范围内；检出限（LODs）在0.001~0.010 mg/kg之间。应用所建立的方法对2007年第四次中国总膳食研究项目的9类膳食样品基质中的氨基甲酸酯类农药进行了检测，在少量样品中检出了涕灭威和克百威。

Determination of N-methyl carbamate pesticides in diet samples by high performance liquid chromatography-linear ion trap mass spectrometry with gel permeation chromatography cleanup

A method for the determination of N-methyl carbamate (NMC) pesticides in diet samples was developed by high performance liquid chromatography-linear ion trap mass spectrometry (HPLC-LIT-MS). The samples with the isotope internal standard were ultrasonically extracted with acetonitrile saturated with cyclohexane, and then cleaned-up by passing through gel permeation chromatographic (GPC) column. The LC separation was performed on a CAPCELL PAK CR column (100 mm×2.1 mm, 5 μm; SCX-C₁₈ (1:4)) using acetonitrile and 5 mmol/L ammonium formate/0.1% (v/v) formic acid aqueous solution as mobile phases (gradient elution) at a flow rate of 0.2 mL/min. The ionization of the analytes was performed by positive electrospray mode. Selective reaction monitoring (SRM) was used for the monitoring of MS³ transitions for each compound. The internal standard was used for quantitation. The average recoveries were in the range of 60.4%-114%, and the relative standard deviations (RSDs) were all not more than 16.2%. The limits of detection (LODs) were 0.001-0.010 mg/kg. The method was successfully applied to the determination of 15 compounds of interest in nine foodstuffs from the fourth Chinese Total Diet Study (TDS) performed in 2007, and aldicarb and carbofuran were found in several samples.