快速溶剂萃取-气相色谱法同时测定土壤中8种有机氯农药

Determination of eight kinds of organochlorine pesticides in soil by rapid solvent extraction-gas chromatography

建立了一种土壤中有机氯农药的气相色谱分析方法。采用快速溶剂萃取仪对土壤中的8种六六六、滴滴涕单体进行萃取,对程序升温条件进行优化,确立了最佳检测方案。采用电子捕获检测器,Elite-1701色谱柱(柱长:30m,内径:0.32mm,填料粒径:0.25μm),填料为14%氰丙基苯基(其中7%氰丙基7%苯基)二甲基聚硅氧烷(86%),载气流量1.0mL/min,程序升温,分流/不分流衬管。当取土样为15g时,8种有机氯农药的检出限在0.11×10~(-6)mg·kg~(-1)~0.67×10~(-6)mg·kg~(-1)之间,定量限在0.33×10~(-6)mg·kg~(-1)~2.67×10~(-6)mg·kg~(-1)之间。标准曲线在40μg·L~(-1)~400μg·L~(-1)范围内线性关系良好,相关系数r在0.998~0.9997之间,8种有机氯农药测定的相对标准偏差在1.7%~3.3%之间,加标回收率在71.4%~97.9%之间。该方法简单、快速,且准确度和精密度较高。具有较宽的线性范围,较低的检出限。同时在样品前处理过程中大大节约了萃取时间和溶剂用量。

The optimal detection method was established,by means of optimizing the program heating conditions,inlet temperature,and the used of rapid solvent extractor.Using flame photometric detector,Elite-1701 column(column length:30m,inner diameter:0.32mm,packing particle:0.25µm).The filler was 14%cyanopropyl phenyl(including 7%cyanopropyl 7%phenyl)dimethylpolysiloxane(86%),with a carrier gas flow rate of 1.0 ml/min,program heating,split inert Liner.The detection limits of eight kinds of organochlorine pesticides were in 0.11×10-6 mg/Kg—0.67×10-6 mg/Kg,and the quantifacation limits were 0.33×10-6 mg/Kg—2.67×10-6mg/Kg,when the sample weight was 15g.Standard solutions of the eight kinds of organochlorine pesticides had good linear relations between 40µg/L and 400µg/L(correlation coefficients R were 0.998—0.9997).The relative standard deviation for the determination of the eight kinds of organochlorine pesticides were 1.7%—3.3%.The standard addition recoveries of samples were 71.4%—97.9%.The method is simple,fast,and has precisions and accuracy,while greatly saving extraction time and solvent usage during sample pretreatment.