液相色谱法测定水中16种多环芳烃的方法优化  

Optimization of liquid chromatography method for detection of 16 polycyclic aromatic hydrocarbons in environmental water

作　　者：王超[1] 彭涛 吕怡兵[1] 滕恩江[1] 

机构地区：[1]中国环境监测总站,北京100012 [2]扬州市环境监测中心站,扬州225007

出　　处：《环境化学》2014年第1期62-68,共7页Environmental Chemistry

基　　金：863计划(2013AA06A308)资助

摘　　要：从色谱条件、溶剂置换条件和萃取液浓缩方式等对水中16种PAHs的液液萃取-液相色谱方法进行了优化研究.结果显示,超高压液相色谱的分析时间(20 min)和消耗的有机溶剂(6.6 mL)分别为高效液相色谱的59%和18%,其标准曲线的线性关系、仪器的精密度和灵敏度也优于高效液相色谱,但对部分PAHs不能实现基线分离.二氯甲烷会引起苯并(a)芘和苯并(g,h,i)苝荧光信号的显著增强,加入5 mL乙腈可使溶剂中的二氯甲烷置换充足,避免荧光信号的异常.氮吹过程中,剩余体积需保持在0.2 mL以上,以减少2—3环PAHs的损失.对于大体积萃取液的浓缩方式,旋转蒸发法可减少2—3环PAHs的损失,使16种PAHs的平均回收率(99.6%)高于氮吹法(77.6%).两种加标水平的实验结果显示16种PAHs的回收率为84.2%—108.5%(RSD 2.2%—7.3%).优化后的方法稳定可靠,可为广大环境监测及科研人员准确分析水中16种PAHs提供参考.To quantify 16 polycyclic aromatic hydrocarbons in environmental water,we developed a liquid-liquid extraction/liquid chromatography（LC） method by optimizing chromatographic condition,solvent-displacement condition,extract-concentration means. Compared with high performance liquid chromatography（HPLC）,the developed ultrahigh-pressure liquid chromatography（UPLC） method has reduced analysis time and less consumption of organic solvent （less than one fifth）,and better linear correlation coefficient,precision and limit of detection （LOD）. However,several PAHs could not be separated by baseline in UPLC probably due to the limitation of the used stationary phase. We also observed that methylene chloride could increase the fluorescent intensity of benzo（a）pyrene and benzo（ghi）perylene. To maintain the fluorescence signal,5 mL acetonitrile was used to displace methylene chloride in solvent. To ensure high recovery of low-ring PAHs,the residual volume of the sample extract should be left above 0.2 mL after nitrogen blowing. To further concentration of bulk of extract,rotary evaporation was used to reduce the loss of 2—3 rings PAHs. Recoveries of 16 PAHs are in the range of 84.2%—108.5% （RSD 2.2%—7.3%） for two spiked levels. The optimized method is rugged,reliable and useful for accurate determination of 16 PAHs in environmental water.

关 键 词：多环芳烃 液相色谱 液液萃取 优化 

分 类 号：X832[环境科学与工程—环境工程] O657.72[理学—分析化学]