This paper describes the combined use of liquid chromatographic separation with multiwavelength absorption detection for the quantitation and Identification of polynuclear aromatic hydrocarbons. Quantitative results are presented for three-and fourcomponent mixtures with complete and partial separation. Qualitative data are presented for a twelve-component synthetic mixture and for extracts from a filter used to collect particulate emissions from a biomass-gasifier system. It is shown that multiwavelength data-processing methods commonly applied to absorption spectra can be applied with significant advantage to second-derivative spectra. Results indicate that significant improvements can be achieved by the use of different wavelength ranges for different components in mixtures. Detection limits for single-component samples varied between 3 and 11 pg 1-l for eleven hydrocarbons and the scatter about calibration plots for mixtures was in the range of 0.05 to 0.4 rg ml-'. The identities of all twelve components in the synthetic mixture were confirmed and nineteen components were identified in the sample from the biomass gasifier filter.
With the advent of low-cost computers capable of acquiring and processing complex data sets, it has become possible to make more effective use of information obtainable from each of several steps in a chemical determination than was possible in the recent past. By making more complete use of the combined capabilities of chemical reaction, separation, measurement, and data-processing steps, it is frequently possible to achieve performance characteristics that are superior to more conventional approaches that focus primary attention on just one step in the process. One of these multidimensional approaches that has received significant attention recently has involved the combination of liquid chromatographic separations with multiwavelength absorption measurements and a variety of data-processing options [ 1, 21. Although the principal focus has been on quantitative applications, these combined processes also have significant promise for qualitative applications. This paper explores the capabilities of this general approach for the quantitation and identification of polynuclear aromatic hydrocarbons (PAH) in mixtures. Quantitative results are presented for synthetic mixtures that are and are not completely separated and qualitative data are presented for synthetic mixtures and for samples from a biomass gasifier system.