膜固相萃取-气相色谱法测定饮用水中有机氯农药的技术优化与质量控制研究

Study on technical optimization and quality control of determination of organochlorine pesticides in drinking water by disk solid phase extraction-gas chromatography

目的建立膜固相萃取-气相色谱法测定饮用水中有机氯农药六氯苯、α-六六六、γ-六六六、七氯、β-六六六、δ-六六六、p,p’-DDE、o,p’-DDT、p,p’-DDD、p,p’-DDT的方法,以加标回收-质控图进行评估,保证检测的质量水平。方法采用47 mm的C18固相萃取膜富集1 L饮用水样品,以二氯甲烷和乙酸乙酯洗脱后浓缩至1 m L。采用VF-1701ms型色谱柱,程序升温分离六氯苯、α-六六六、γ-六六六、七氯、β-六六六、δ-六六六、p,p’-DDE、o,p’-DDT、p,p’-DDD、p,p’-DDT,经电子捕获检测器测定,外标法定量。结果10种有机氯农药标准于10~100μg/L范围内线性良好,相关系数>0.9988,方法检出限为3~5 ng/L,低、中、高浓度平均加标回收率为87.7%~116.0%,相对标准偏差为8.3%~15.4%。加标回收质量控制图(n=20)中心线为91.8%~115.3%,标准偏差(s)为11.5%~14.1%。结论本研究应用于饮用水监测具有高度的普及性,便捷高效,加标回收-质控图可有效控制检测的质量水平。

Objective To establish a method for the determination oforganochlorine pesticides,including hexachlorobenzene,αHCH,γ-HCH,heptachlor,β-HCH,δ-HCH,p,p'-DDE,o,p'-DDT,p,p'-DDD and p,p'-DDT,by using disk solid phase extractiongas chromatography,evaluate with recovery rate-quality control chart to ensure the quality level of testing.Methods 1 L drinking water sample was enriched by using a 47 mm C18 solid-phase extraction membrane,and methylene chloride and ethyl acetate were used for elution,and the constant volume was 1 mL.The hexachlorobenzene,α-HCH,γ-HCH,heptachlor,β-HCH,δ-HCH,p,p'-DDE,o,p'-DDT,p,p'-DDD and p,p'-DDT were separated by temperature programming with chromatographic column VF-1701 ms,and electron capture detector was used to collect data.The quantitation was carried out by the external standard method.Results 10 kinds of organochlorine pesticides showed the good linearity in 10-100μg/L,and the correlation coefficientswere>0.9988.The limits of detectionwere 3-5 ng/L.The average recoveries ranged from 87.7%to 116.0%for low,medium,and high concentrations,and the relative standard deviations were 8.3%-15.4%.The center lines of recovery rate-quality control chart(n=20)ranged from 91.8%to 115.3%,and standard deviations(s)were in the range of 11.5%-14.1%.Conclusion This method is simple,quick,and widely used in drinking water monitoring,and the recovery rate-quality control chart can improve the quality of inspection.