Researches On The Determination Methods Of Polycyclic Aromatic Hydrocarbons (PAHs) In Environmental Water By HPLC

Polycyclic aromatic hydrocarbons (PAHs) are recognized as the main cause of "three hurts" (carcinogenic, teratogenic and mutagenic capabilities).It is very important to test the concentration of PAHs in the water accurately.Our country released the latest environmental protection standard named as the water quality determination of polycyclic aromatic hydrocarbons, using liquid-liquid extraction, solid-phase extraction and high performance liquid chromatography (HJ 478-2009). Due to the universality of the standard the specific detection needs to be further confirmed when it is applied in our enterprise detection.Through experimental researches, based on the latest environmental protection standard, the specific operation procedures have been developed including liquid-liquid extraction of samples with methylene chloride, concentration using the TurboVap Ⅱ blowing nitrogen instrument, substitution, separation with PAH column, gradient elution with 40% acetonitrile and 60% water flow phase, qualitative and quantitative identification with diode array detector and fluorescence detector. Established methods have good linear correlation coefficients (> 0.999)in 0.5-5 mg/L measured range, and the relative standard deviation is less than 15% for repeated measurements of the standard sample. When liquid-liquid extraction and scalar are 2μg, the labeled recovery rates of 16 kinds of PAHs are between 65.2%-99.1%, and the detection limit of benzo (a) pyrene using fluorescence detector is 0.001 μg/L. The results meet the requirements of the standard.The contents of 16 PAHs of the bio-chemical treatment effluent in the Baosteel 1 st & 2 nd phase project are detected by using this method. The contents of 6 specific PHAs set by the state are listed as followed:the total contents of benzo (a) pyrene, fluoranthene, benzene and (b) fluoranthene, benzene and fluoranthene, indene (k) and (1,2,3-c, d) pyrene and benzo (g, h, I)) are 4.811 μg/L, and the contents of benzo (a) pyrene are 1.101 μg/L. In the external drainage of the Baosteel 1 st & 2 nd & 3rd phase project 6 kinds of particular PAHs are not detected. Established methods have good linear correlation coefficients (>0.999) in 0.5-5mg/L measured range, and the relative standard deviation is less than 15% for repeated measurement of the standard sample.When liquid-liquid extraction and scalar are 2μg, the labeled recovery rates of 16 kinds of PAHs are between 65.2-99.1%, and the detection limit of Benz (a) pyrene is 0.001μg/L using fluorescence detector.The results meet the requirements of the standard. The results are far lower than the discharge limits,which of the contents of 6 special PAHs in the water pollutant discharge are not more than 50μg/L, and the contents of benzene and (a) pyrene are not more than 0.03 μg/L according to the national standard requirements.Using the method -analysis results of two external drainage are basically identical with the results analyzed by the Shanghai Environmental Monitoring Center(SEMC).This method can satisfy the determination demand on the PAHs in external drainage.