Analysis Of Substituted And Parent Polycyclic Aromatic Hydrocarbons In Groundwater

Polycyclic aromatic hydrocarbons(PAHs)are hydrocarbons which contain two or more benzene rings.PAHs are kinds of contaminants with strong effects of carcinogenic,teratogenic and mutagenic.Represented by Benzo[a]pyrene,16 PAHs have already been classified to the priority control pollutants by US EPA in the 70 years of the twentieth century.But in recent years,substituted polycyclic aromatic hydrocarbons(SPAHs)have been discovered together with PAHs,they are more toxic,more polar than their parent PAHs and the content of it is fairly high.Groundwater,used mostly for drinking,agriculture and industry,plays a vital role in human survival,economic development and social harmony in China.The quality of groundwater has got more and more attention,and the detection of traditional contaminants in groundwater has become increasingly common.Therefore,it is necessary to establish efficient,sensitive and accurate analysis methods of substituted PAHs and detect the content of substituted PAHs in the groundwater of our country.For the need of the survey of emerging organic pollutants in groundwater,this paper selected part of the substituted and parent of PAHs as target compounds,and established the analysis method based on the gas chromatography-mass spectrometry.Meanwhile,the method was used to investigate the groundwater pollution in eastern China.The major achievement of this paper are as follows:1.The confirmation of the target compounds37 substituted and parent PAHs have been selected as target compounds including 9 oxy-PAHs,5 Cl-PAHs,4 N-PACs,3 hydro-PAHs and 16 US EPA priority control PAHs.2.Sensitive and accurate instrument analysis method has been establishedFor the difficulties that substituted and parent PAHs have much isomers which lead to poor separation,this paper optimized on its analysis method.GC-MS and GC-MS/MS instrument methods have been established by the optimization of various analytical conditions.The methods with high degree of separation,good sensitivity and high accuracy for targets.Finally,this paper selected the DB-Select PAH capillary column dedicated for PAHs to depart,quantify by internal standard and complete the analysis of all the objects within 30 minutes.3.Pre-treatment analysis methods of water samples have been establishedIt is difficult to get high recoveries of all the substituted and parent PAHs with different physical and chemical properties,simultaneously.This paper developed comparative study of liquid-liquid extraction,solid phase extraction and sorptive stir bar extraction.Duo to the good recoveries and stabilities of the most targets,the liquid-liquid extraction was selected as the pre-treatment analysis method,finally.4.Screening of substituted and parent PAHs in groundwater of east China for the first timeA survey of SPAHs and PAHs in Groundwater along the Grand Canal from Hangzhou to Beijing,East China have been carried out.14 cities of eastern China was investigated in this paper.Among 64 sampling sites,30 targets were detected out among the all 37 target compounds including 14 SPAHs and 16 PAHs.Among the 14 SPAHs,anthraquinone,9-Fluorenone,benzo[a]fluorenone and benzanthrone have higher detection rate,which exceed 50%;9-Fluorenone,anthraquinone,1-chloronaphthalene and carbazole have higer concentrations,the maximum concentration were 62.6 ng/L,154 ng/L and 71.7 ng/L,respectively.Among the 16 PAHs,phenanthrene,pyrene,fluoranthene and chrysene have higher detection rate,which exceed 50%;naphthalene,benzo[b]anthracene and benzo[g,h,i]perylene have higer concentrations,the maximum concentration were 809 ng/L,245 ng/L and 202 ng/L,respectively.The mean value of most targets were range from 1.2 to 16.7 ng/L with lower values.The above results show that groundwater was in the low level of pollution of most areas,but it indeed received the serious pollution in a few areas.