凝胶色谱在线净化-气相色谱-质谱联用快速测定土壤中六六六和滴滴涕残留

Rapid GC-MS Determination of BHC and DDT Residues in Soil After Purification by On-line Gel Permeation Chromatography

采用加速溶剂萃取（ASE）及凝胶色谱（GPC）在线净化，实现了土壤中六六六及滴滴涕的8种异构体或同系物残留量的气相色沓质谱（GC-MS）联用快速测定。以二氨甲烷-丙酮（1＋1）为溶剂，采用加速溶剂萃取土壤样品，萃取液经合并，蒸干后溶于10mL丙酮中，通过GPC-GC-MS联用仪可实现净化后直接在线检测，检测模式为离子监测（SIM）模式，利用保留时间和特征离子进行定性，外标法定量。在此检测方法下，8种有机氯农药在0．02～0．4mg·L^-1范围内呈线性关系，检出限（3s／N）在0．0147～0．0783ug·kg^-1之间，加标回收率在101．4％～129．5％范围内。

Rapid C-C-MS determination of residual amounts of 8 isomers or homologues of BHC and DDT in soil was achieved by separation with accelerated solvent extraction （ASE） and purification with on-line gel permeation chromatography （GPC）. Mixed solvent of dichloromethane and acetone （1 to 1 by vol. ） was used as the extraction solvent in ASE, and the extracts obtained were combined and evaporated to near dryness. The residue was taken up with acetone, diluted to 10 mL and used for GC-MS analysis after purification by the on-line GPC. The mode of SIM was used in the MS-detection. Qualitative analysis was performed based on the retention time and characteristic ions, and quantitative analysis was carried out by the external standard method. Linear relationships between values of peak area and concentration of the 8 pesticides were obtained in the same range of 0. 02 to 0. 4 mg· L^-1 , with their detection limits （3S/N） in the range of 0.014 7--0. 078 3ug·kg^-1. Results of recovery test were found in the range from 101.4% to 129. 5%.