加速溶剂萃取-固相萃取净化-气质联用法测定稻谷中18种农药残留

An Accelerated Solvent Extraction-Solid Phase Extraction-Gas Chromatography/Mass Spectrometry Method for Determination of 18 Pesticides in Paddy

中文关键词:  加速溶剂萃取  固相萃取  气相色谱-质谱法  稻谷  农药残留

英文关键词:ASE  SPE  GC/MS  paddy  pesticides

中文摘要:

      建立了加速溶剂萃取-固相萃取净化-气质联用法（ASE/SPE/GC-MS）测定稻谷中18种农药残留的方法.以乙腈为溶剂，样品经加速溶剂萃取（30 mL萃取池中，10.34 MPa压力、80℃条件下，加热5 min，用乙腈静态萃取3 min，循环2次，再用池体积60%的乙腈冲洗萃取池后用氮气吹扫100 s）后，过自制固相萃取柱净化（萃取速率：1滴/秒），洗脱旋蒸后正己烷定容，使用气相色谱-质谱联用仪分析.在优化条件下，18种农药在0.05~1.0 μg/mL质量浓度范围内的相关系数R²均大于0.99，浓度与峰面积之间呈良好的线性关系.分别以3倍标准偏差和8倍标准偏差计算检出限和定量限，18种农药的检出限为0.104~0.647 mg/kg，定量限为0.276~1.724 mg/kg.以空白样品为基体进行加标回收试验，平均回收率在82.5%~105.1%之间，相对标准偏差（RSD，n=6）为1.5%~6.4%.方法适用于稻谷中18种农药残留的检测.

英文摘要:

      A gas chromatography/mass spectrometry(GC/MS) method was established for the determination of 18 pesticides in paddy based on the accelerated solvent extraction (ASE) method:in the 30 mL extraction pool under a pressure of 10.34 MPa, heating for 5 min at 80℃, and static extracting with acetonitrile for 3 min, cycling for 2 times, then washing the extraction pool with acetonitrile of 60% of the pool volume, then purging for 100 s with nitrogen. And then a solid phase extraction (SPE) column with an extraction rate of 1 drop/second was used for the purification of sample. In this method, the samples were first extracted with acetonitrile, and then purified by SPE column and evaporated to dryness in a rotary evaporator. The pretreated samples were re-dissolved in n-hexane to a constant volume for the determination by GC/MS. Linear relationships between values of peak area and mass concentration of 18 pesticides were found in the range of 0.05~1.0 μg/mL, all of their linear correlation coefficients were more than 0.99. The limits of detection were 0.104~0.647 mg/kg, and the minimum quantitative limits were 0.276~1.724 mg/kg. The spiked recoveries were between 82.5%~105.1%, and the RSDs were between 1.5%~6.4%. The method is suitable for the determination of 18 pesticides in paddy.