漩涡辅助液液微萃取测定水样中有机氯和菊酯类农药

Determination of organochlorine pesticides and pyrethroids pesticides in water samples using vortex assisted liquid- liquid microextraction and gas chromatography

目的建立采用漩涡辅助液液微萃取前处理技术,GC-ECD为色谱检测仪器,测定环境水样中有机氯和菊酯类农药残留的分析方法。方法方法考察了萃取剂种类、萃取体积、萃取时间、漩涡速度、盐浓度对萃取效率的影响,对各种影响条件进行了优化,确定了最佳萃取条件为:在25 ml容量瓶中依次加入1 g NaCl,20 ml水样,再用微量注射器加100μl萃取剂正己烷,在2500 r/min旋涡2 min,静置分层,萃取层供色谱分析。结果该方法在0.05 mg/L^1.00 mg/L浓度范围内呈良好的线性关系,线性相关系数为0.995~0.999,方法检出限为0.005μg/L^0.1μg/L(S/N=3),方法的添加回收率为85%~110%,6次平行测定的相对标准偏差为3.5%~10%。结论操作简单、快速、成本低、环保高效、富集效率高等优点,能满足环境水样中有机氯和菊酯类农药检测需要。

Objective A vortex assisted liquid - liquid microextraction has been developed and used for extraction of organo- chlorine and pyrethroids pesticides from water samples, followed by gas chromatography micro cell electron capture detection （GC -ECD）. Methods The influence of extraction parameters, including the types and volumes of extraction solvent, agita- tion speed, extraction time as well as salt - effect, were investigated to set the optimal extraction conditions. 1 g NaC1 and 20 ml water sample were put into 25 ml volumetric flask in turn, then 100 μl n - Hexane as extraction solvent was directly injected into the volumetric flask for vigorously shaking 2 min with the vortex at 2500 r/min. The chromatographic analysis was performed fol- lowing static stratification. Results The proposed method provided a linear range of 0.05 mg/L - 1.00 mg/L with r between 0.995 -0.999, the detection, limit was 0.005 μg/L -0.1 μg/L（S/N =3）, RSD was 3.5% -10% （n=6） and the standard recovery rate was between 85% - 110%. Conclusion The method can be applied to the routine analysis of organochlorine pes- ticides and pyrethroids pesticides in water samples, due to the advantages of easy operation, rapidity, low cost, environmentally friendliness and high enrichment efficiency.