炼油废水中有机污染物的气相色谱分析

Analysis of Organic Pollutants in Refinery Wastewater by Gas Chromatography

建立了采用液液萃取法对炼油废水进行预处理,然后用气相色谱法对处理后的含有苯系物、酚类化合物、直链烷烃、胺类化合物和多环芳烃类化合物等18种有机污染物的废水进行快速分析的方法,考察了萃取剂种类和萃取次数等条件对萃取效果的影响,同时得到了18种有机污染物的标准工作曲线。实验结果表明,最佳萃取剂为二氯甲烷;最佳萃取条件为:先在碱性条件下萃取3次,然后在酸性条件下萃取3次。该方法采用HP-5(30 m×320μm×0.25μm)毛细色谱柱,FID检测,外标法定量。各组分的检出限均在0.05～0.29 mg/L内,相对标准偏差小于10.8%;除苯酚外,其他组分的回收率为85.0%～104.9%,能满足炼油废水快速监测的需要。

An analytical method for the organic pollutants in refinery wastewater was established.The analysis was carried out by liquid-liquid extraction pretreatment and then gas chromatography.The analytical method with GC-FID was used to detect the complicated composition of the refinery wastewater which mainly contained benzenoid hydrocarbons,phenols,linear alkanes,aromatic amines and polycyclic aromatics.The effects of extractant type and extraction times on the extraction yields were investigated.The standard curves of 18 organic pollutants were obtained.The results indicated that the optimal conditions were extracting 3 times under alkaline condition and then extracting 3 times again under acidic condition with dichloromethane as the extractant,and HP-5（30 m×320 μm×0.25 μm） capillary column,FID detector and external standard method.Under the optimal conditions,the detection limits were in the range of 0.05-0.29 mg/L and the relative standard deviation was less than 10.8%.Except for phenol,the recoveries of the other compounds were in the range of 85.0%-104.9%.