LLE-GC-MS法测定地表水中23种痕量含氯有机污染物

Simultaneous Determination of 23 Trace Chlorinated Organic Pollutants in Surface Water with LLE-GC-MS Method

建立了以液液萃取(LLE)-气相色谱-质谱-SIM扫描(GC-MS-SIM)技术同时检测城区河道表层水样中16种有机氯农药和7种多氯联苯残留的分析方法。样本量为200 mL时,方法检出限(S/N≥3)为0.5~12.5 ng/L,空白水样平均加标回收率在77.8%~110.1%之间,线性范围内方法准确度和精密度范围分别为89.4%~103.5%(n=6)和0.7%~9.9%(n=18),满足方法学要求。采用该方法对流经济宁市境内3条河流表层水样进行检测,结果显示17个站位表层水样中普遍检出艾氏剂、α-氯丹、γ-氯丹、o,p′-DDT和PCB 52,部分站点污染程度超出GB 3838—2002标准限值。该方法结果准确可靠,具有较高的灵敏度和准确度,且操作简便、成本较低,能够满足地表水水质监测的需要。

A method for detecting 16 organochlorine pesticides(OCPs)and 7 polychlorinated biphenyl(PCBs)residues in surface water in urban rivers simultaneously using the liquid-liquid extraction(LLE)method,combined with gas chromatography-mass spectrometry-SIM scanning(GC-MS-SIM),was established.For 200 mL of detecting samples,the detection limits of the method(S/N≥3)were 0.5~12.5 ng/L,and the average recoveries ranged from 77.8%to 110.1%.The accuracy and precision of the method were in the range of 89.4%~103.5%(n=6)and 0.7%~9.9%(n=18),respectively,which met the methodological requirements,among the range of the linear relationship.The method was then used to detect the surface water samples of three rivers in Jining City,Shandong Province.The results showed that aldrin,α-chlordane,γ-chlordane,o,p′-DDT,and PCB 52 were generally detected in the surface water samples of 17 stations,and the pollution degree of some stations exceeded the standard limit of GB 3838—2002.The pollution degrees of dichlorodiphenyltrichloroethane(DDTs)and PCBs exceed the corresponding environmental thresholds and are urgently paid social attention and treated.It can be concluded that the method developed has high sensitivity and accuracy as well as simple operation and low cost,that could meet the needs of quality monitoring in surface water.