固相萃取—气质联用测定水中23种有机氯有机磷农药污染物

Determination of 23 Organochlorine and Organophosphorus Pollutants in Water by Solid Phase Extraction and GC-MS

目的 建立固相萃取—气质联用法同时测定水中多种有机磷、有机氯农药,监测江苏省部分地区饮用水中有机氯、有机磷农药污染状况。方法 采集江苏省部分地区13个水厂的水源水和出厂水样,用PLS固相萃取小柱富集水中的有机氯、有机磷农药,用1∶1的乙酸乙酯二氯甲烷洗脱,采用气相色谱—质谱联用仪测定,农药的保留时间和特征质量离子进行定性分析,以峰面积为定量指标,采用内标法计算样品中的农药残留量。结果 在0.2~1.0 mg/L浓度范围内,各组分检测响应值与浓度呈良好线性关系,相关系数均大于0.997。检出限为0.3~6.4 ng/L,加标回收率为70.0%~118.0%,相对标准偏差(RSD)为4.5%~12.3%。共检测水源水和出厂水49个水样,有机磷农药中敌敌畏检出率为100%、有机氯农药中β-六六六、林丹、检出率为58.3%~100%,28.0%~41.7%。结论 该方法可同时分析水中23种有机氯、有机磷农药;江苏省部分地区饮用水中敌敌畏、β-六六六、林丹等检出率较高。提示今后应加强相关项目的环境安全风险监测与评价,同时建议有关部门尽快制定相关项目的标准限值。

Objectives To establish a quantitative method to detect the pollution of organochlorine and organophosphorus pesticide in drinking water in some regions of Jiangsu province with a method of combining solid phase extraction and gas chromatography-mass spectrometry. Methods Source water and finished water samples were collected from 13 water plants in Jiangsu province. Organochlorine and organophosphorus pesticides in drinking water samples were extracted by PLS solid-phase extraction column and then eluted by ethylacetatemethylene chloride( 1 ∶ 1),and were detected by gas chromatography-mass spectrometry. The specific retention times,qualifier and target ions, and the qualifier /target abundance ratio were used to identify individual pesticides. Quantifications were based on internal standard addition. Results The linear ranges of standard curves for target compounds were 0. 2 ~ 1. 0 ng /L and the R2values were greater than 0. 997. The detection limits,recovery rates and relative standard deviations( RSD) were 0. 3 ~ 6. 4 ng /L,70. 0% ~ 118. 0% and 4. 5% ~ 12. 3%,respectively. In 49 source water and finished water samples,the detection rate of organophosphorus pesticide dichlorvos was 100% and the detection rates of organochlorine pesticide β-BHC and lindane were 58% ~ 100%and 28. 0% ~ 41. 7%,respectively. Conclusions The pollution of 23 kinds of organochlorine and organophosphorus pesticides could be detected by this method. Dichlorvos,β-BHC and lindane were detected in higher rates.Monitoring and evaluating the environmental risks of pesticide pollution should be strengthened,and relevantdepartments should be urged to develop standard limits for the residue of pesticides.