液液萃取-C18固相膜萃取-气相色谱/质谱联用测定地下水中半挥发性有机物

采用液液萃取法和C₁₈固相膜萃取法对水样进行前处理,利用气相色谱/质谱联用技术进行分析测定,通过回收率实验和精密度实验对两种前处理方法进行比较。在加标回收实验中，液液萃取法的加标回收率普遍低于65%，不符合US EPA标准（70%~130%），而C₁₈固相膜萃取法的加标回收率都在70%~120%之间，符合US EPA标准；在精密度实验中，液液萃取法的相对标准偏差在30%以内，而C₁₈固相膜萃取法的相对标准偏差均不超过20%，两者均符合US EPA标准（<30%），但是C₁₈固相膜萃取法的实验效果更好。从实验中得出，C₁₈固相膜萃取法是地下水样较好的前处理方法。利用所研究的方法分析了北京市某生活区的地下水样，在该水样中检出了63种有机化合物，包括1种酯类、1种醇类、2种酸类、2种酚类、2种氯代烃、25种苯系物、4种烯烃、14种烷烃和12种多环芳烃。

Determining Semi-volatile Organic Substances of Groundwater through Liquid-liquid Extraction-C18 Membrane Disk Extraction-GS/MS

The groundwater samples are pretreated respectively by means of both the liquidliquid extraction and the C18 membrane disk extraction, analyzed with the GS/MS. The recovery and precision experiment are both conducted to compare the two pre-treatment methods. The recovery of the liquid-liquid extraction with standard samples are generally smaller than 65%, while those of the later with that all vary from 70% to 120%. The relative standard deviations of the liquid-liquid extraction are all less than 30%, while those of the C18 membrane disk extraction are less than 20%. In the recovery experiment spiked with standard samples, The results show that the C18 membrane disk extraction is optimal. The groundwater samples are analyzed and 63 organic compounds are detected.