加速溶剂萃取-气相色谱/串联质谱法测定土壤中20种有机氯农药

建立了用加速溶剂萃取法（ASE）提取、气相色谱-串联质谱法分析土壤中20种有机氯农药的方法。用正己烷和丙酮（1∶1,V/V）的混合溶剂为提取剂,萃取温度100℃,压力1 500 psi,静态提取10 min,循环提取2次,提取液经石墨化碳黑固相萃取柱净化,浓缩后进行GC-MS/MS测定,外标法定量。试验结果表明,采用串联质谱多反应监测模式,降低了背景干扰,当取5 g土壤时,有机氯农药的检出限在0.1~3.0μg/kg之间,低浓度水平（8μg/kg）的基体加标回收率为70.3%~134%,相对标准偏差〈23%。测定方法背景干扰低,灵敏度高,适合土壤中20种有机氯农药残留的同时测定。

Determination of 20 Organochlorine Pesticides in Soils Using Gas Chromatography tandem Mass Spectrometry Coupled with Accelerated Solvent Extraction

A method was developed for the determination of 20 organochlorine pesticides in soils based on accelerated solvent extraction（ ASE） and gas chromatography-tandem mass spectrometry（ GC-MS / MS）. Organochlorine pesticides were extracted with n-hexane-acetone（ 1∶ 1,V / V） solution with the extraction temperature of 100℃ and the pressure of 1 500 psi. After the static extraction for 10 min of 2 circulation,the extracts was cleaned up by Carbon solid-phase extraction（ SPE） column. The detection of 20 Organochlorine pesticides was carried out by GC-MS / MS in the multi-reacting monitoring（ MRM） mode using external standard method. When sample amount was 5 g,the detection limit was between 0. 1 ~ 3. 0 μg / kg. When the spiked concentration was at low level（ 8 μg / kg）,the average recoveries were in the range of 70. 3% ~ 134% and the average standard deviations（ RSDs） were less than 23%. The method possesses low background and high sensitivity. It can be applied to the routine analysis of the 20 Organochlorine pesticides in soils.