Determination of polycyclic aromatic hydrocarbons in biomass gasifier effluents with liquid chromatography/diode array spectroscopy.

Liquid chromatography/diode array spectroscopy (LC/DAS) is used for the determination of polycyclic aromatic hydrocarbons (PAH) isolated from the emissions of biomass gasifiers. The spectrometer is capable of obtaining complete absorption spectra of components as they elute from the chromatograph, thus confirming the identities of pure peaks and mixed or poorly resolved peaks. This technique is especially well suited for the determination of polynuclear aromatics, where many isomers difficult to resolve chromatographically are easily distinguished by their electronic spectra. The instrument is also capable of differentiating between unsubstituted PAH and their methylated analogues, even though methylation does not greatly perturb the electronic nature of the parent hydrocarbon.