Feasibility of Polycyclic Aromatic Hydrocarbon Measurements in a Near-Sooting C2H2/O2/N2Flame using HPLC with Fluorescence Detection

Publisher Website
Google Scholar
Abstract
Mole fraction profiles for phenanthrene, anthracene, fluoranthene, and pyrene have been determined for a premixed, flat C2H2/O2/N2 flame at a pressure of 140 torr and an equivalence ratio of 1.79. Gas samples from within the flame were pulled through a small diameter quartz probe and collected on an XAD-2 resin column. Following column extraction and sample preparation, the samples were analyzed using two high pressure liquid chromatography (HPLC)/fluorescence detection systems. The measured detection limits ranged from 10−10 to 10−9 mole fraction. One HPLC system employed a standard fluorometric detector which has an excitation wavelength of 254 nm and monitors fluorescence at wavelengths greater than 370 nm. The second detector consists of a N2 laser for excitation at 337.1 nm, an emission monochromator, and a 2-channel sampling oscilloscope to monitor the fluorescence at 416-424 nm. Two fluorescence measurements were taken 10 ns apart after each laser pulse to enable determination of the fluorescence lifetimes of the eluting species. A method is proposed utilizing the HPLC/fluorometer detection system for initial identification and quantification of species, and the HPLC/N2 laser system for verification of identity and determination of peak purity.