Research On Characteristic Spectral Detection Technologies Of Polycyclic Aromatic Hydrocarbons In Atmospheric Aerosol

In order to select a fast, precise and simple measurement technology for on-line monitoring the component and concentration of polycyclic aromatic hydrocarbon (PAH) mixtures in atmospheric aerosol, this study performs a plenty of simulation experiments in the laboratory to make the comparison among three different types of spectrometry analysis technologies which are constant energy synchronous luminescence spectrometry, UV-Vis spectrometry and Fourier Transform Infrared Spectroscopy respectively. Then, measuring conditions of the selected technology are optimized using orthogonal experiments, and 15 PAHs characteristic spectrum-base is constructed, a new method for qualitative and quantitative spectroscopic data analysis without pre-separation courses is established. The results show that:1. Constant energy synchronous luminescence spectrometry is the fittest measurement technology of above three spectroscopic measurement methodologies which has the best selectivity, highest sensitivity, optimal precision, lowest detection limit and favorable linear range, and may serve as on-line analysis of multicomponent PAHs in atmospheric aerosol without complex pre-separation courses.2. All of the three factors including photomultiplier voltage, excitation and emission monochromator slit width of fluorescence spectrophotometer have significant influences on precisions, sensitivities, detection limits, while only excitation monochromator slit width significantly affect the peak widths at half-height. The best measuring conditions of simulation tests are photomultiplier voltage of 800V, excitation and emission monochromator slit widths of 2.5nm and 5nm respectively.3. The best measuring△v for 15 PAHs are listed:1500cm-1 (Anthracene, Benzo[a]pyrene, Benzo[k]fluoranthene, Benzo[ghi]perylene); 3000cm-1(Pyrene); 3600cm-1(Fluorene, Acenaphthene, Chrysene, Dibenzo[a,h]anthracene); 5200cm-1(Benzo[b]fluoranthene, Indeno[1,2,3-cd]pyrene); 7500cm-1 (Naphthalene, Phenanthrene, Fluoranthene); 8800cm-1(Benzo[a]anthracene). Constant energy synchronous fluorescence spectrum-base of 15 PAHs is built depending on these six Av.4. The new method for qualitative and quantitative spectroscopic data analysis without pre-separation courses is set up based on second derivative constant energy synchronous luminescence spectrometry, and the detection limits are 0.073-60.307ng·ml-1. Compared with high performance liquid chromatography jointed fluorescence detector in detecting PAH from atmospheric aerosols, measurement errors means of this new technique ranged from-0.09 to 1.73%, and the results are accurate with very small differences. The lowest detection limits of 9 detected PAHs are 0.026-0.392ng·m-3, and can satisfy with on-line monitoring. An analysis process of this new method takes about 6min, making it suitable for real-time determination of the component and concentration of PAH mixtures in aerosols.