Polycyclic aromatic hydrocarbons (PAHs) in the aerosol in Beijing, China, measured by aminopropylsilane chemically-bonded stationary-phase column chromatography and HPLC/fluorescence detection

摘要

We developed a useful analytical method for the determination of polycyclic aromatic hydrocarbons (PAH) concentrations in the aerosol of China. We used an accelerated solvent extraction (ASE) method for the extraction of PAHs from the aerosol samples, in order to reduce the extraction time and the solvent volume used. The optimum purification method was developed, with aminopropylsilane chemically-bonded stationary-phase column chromatography, in order to remove many co-extractives which cannot be removed by conventional purification methods using silica-gel column chromatography. HPLC/fluorescence detection (FLD) was adopted as the analytical method, because it has very high sensitivity to PAH and it is easy to install, operate, and maintain as compared with GC/MS. With the analytical method developed in this study, the recovery and precision (RSD) for most of the PAHs ranged from 75% to 129% and from 2.8% to 22.7%, respectively. The concentrations of PAHs in the aerosol samples collected from October 2003 to April 2005 in Beijing, China were determined using the newly developed method. ∑PAHs, which is the sum of the concentrations of all detected PAHs, was 177.8 ± 239.9 ng m~(-3) (n = 64). The ∑PAHs concentration in the heating season (305.1 ± 279.0 ng m~(-3), n = 33) was 7.2 times higher than that in the non-heating season (42.3 ± 32.0 ng m~(-3), n = 31). These strong seasonal variations in atmospheric PAH concentration are possibly due to coal combustion for residential heating in winter.