水捕获-气质联用快速分析柴油机排放的多环芳烃

摘要

建立了一种快速采集分析柴油机排放的有毒气态多环芳烃(PAHs)的方法.新的采样方法以水为捕获媒介,通过添加阳离子表面活性剂与多环芳烃相似相溶,避免了使用固体吸附材料带来的样品损失和变性,进而通过优化各种功能性添加剂提高样品回收率.吹扫捕集系统快速从水中富集痕量PAHs.采用气相色谱/质谱联用检测到柴油机排放中包含的16种主要PAHs,总量85.53μg/m3.本法的采样和分析过程所需样品量少,检测速度快,耗时只有经典方法的5％,从而把PAHs的损失降到最低,检测限达到皮克级.%A novel collection and detection method is established for determination of toxic gaseous polycyclic aromatic hydrocarbons (PAHs) emitted from diesel engine.Water-capture-method is processed by adding functional surfactants to solubilize PAHs,and avoids loss and degeneraiton of sample caused by using solid adsorbents.The problems such as poor solubility of PAHs in water and the adsorptions of PAHs on the pipe wall are solved.Inorganic salt and organic solvent are added to improve the solubility and recovery yields of PAHs.The purge-and-trap system can collect PAHs traces from water quickly.GC/MS analysis shows that diesel engine exhaust gas includes 16 dominant PAHs,with a total concentration of 85.53 μg/m3.The entire process requires very few samples,the detection limit reaches to pg grade,the detection speed is fast,and the purge-and-trap time is less than 5％ of the traditional method,which can decrease the PAHs loss as little as possible.