The Analysis Of The Polycyclic Aromatic Hydrocarbon In Aerosol And The Study Of Its Distribution In Qingdao

This paper studies the analytical method for determination of polycyclic aromatic hydrocarbon (PAHs) in aerosol by high performance liquid chromatography (HPLC) with fluorescence detector, according to the structure of PAHs and its characteristic of fluorescence emission. The best excitation wavelength and emission wavelength of PAHs are obtained by wavelength program. Thirteen PAHs are separated successfully by multiple-unit gradient method using Chromsep 3μm chromatograph column and methanol-water as the mobile phase, and designs the wavelength program for determination of PAHs in aerosol by HPLC with fluorescence detector.The optimal separating condition are: column temperature: 30℃,mobile phase: methanol-water, mobile velocity: 1.0ml/min; the composition of mobile phase and separating times condition:a) A (methanol 15%), 18%; B (methanol 100%), 82%, under this condition, remains Tminutes and separating the PAHs with linear gradient for 5 minutes. After then, changing the condition as follows:b) A (methanol 15%), 5%; B (methanol 100%), 95%, operated as step a), and then separating for 17 minutes.Wavelength program table for PAHsWith the optimal condition, the detection limits of the above thirteen kinds of PAHs are 0.90-55.19pg, the recoveries are 92.8%-108%, the relation standarddeviation are 6.0%-25%.With the designed analytical method for the determination of PAHs, we study the concentrations and changes of the fourteen kinds of PAHs in aerosol in the six function zones in Qingdao. The average concentration of the total sum of the thirteen PAHs is32.8ng/m3 in spring, 64.8 ng/m in autumn, 156 ng/m in winter. The average concentration of the BaP in aerosol in spring, autumn and winter are as follows: 2.86 ng/m3,5.63 ng/m3,11.4 ng/m3.The distribution of PAHs in aerosol of Qingdao regions has obviously seasonal characteristics. The average concentration of the fourteen kinds of PAHs changes in order of winter>autumn>winter .It indicates that the PAHs comes mainly from the waste gas pollutants produced by the mineral fuels burning.Different function zone differ greatly in the concentration of PAHs. In the industry zone, the max and min concentration of the total sum of PAHs and BaP were 17times and 13times in winter. Other function zones have the same conditions. The max concentration of PAHs are 76 times in the traffic zone in spring, and the min concentration of PAHs are only 2 times in the control zone.Factor analysis, correlation analysis and SPSS statistics software are used to analyze the contents of PAHs in the six function zones of Qingdao. From the results, we can get the following conclusions:A) PAHs, Py, B(a)An, Chry, BbP, BaF, BaP and DB(a,h)An have good correlation , except Py, the correlation coefficient of the other seven kinds of PAHs are more than 0.90. It indicates that the source of PAHs have the similarity.B) The above 8 kinds of PAHs have good correlation with TSP. This means that TSP is the main factor to affect the concentration level of PAHs. It is a good carrier for PAHs.C) The correlation between PAHs and SO2 is weak, but there exits certain relativity with NOx. However it indicates that the PAHs is related to the pollution sources produced by mineral oil burning.