Parallel Factor Analysis of 4.2 K Excitation-Emission Matrices for the Direct Determination of Dibenzopyrene Isomers in Coal-Tar Samples with a Cryogenic Fiber-Optic Probe Coupled to a Commercial Spectrofluorimeter.

Several studies have shown high concentrations of polycyclic aromatic hydrocarbons (PAHs) in living spaces and soil adjacent to parking lots sealed with coal-tar-based products. Recent attention has been paid to the presence of seven PAHs in coal-tar samples, namely, benz[a]anthracene, benzo[k]-fluoranthene, benzo[b]fluoranthene, benzo[a]pyrene, chrysene, dibenz[a,h]anthracene, and indeno[1,2,3-cd]pyrene, and their association to significant increases in estimated excess lifetime cancer risk for nearby residents. Herein, we present an analytical approach to screen the presence of five highly toxic, high-molecular weight PAHs (HMW-PAHs) in coal-tar samples. These include dibenzo[a,l]pyrene, dibenzo[a,i]pyrene, dibenzo[a,e]pyrene, dibenzo[a,h]pyrene, and naphtho[2,3-a]pyrene. Their direct analysis, without chromatographic separation, in a reference coal-tar sample is made possible with the combination of excitation-emission matrices (EEMs) and parallel factor analysis (PARAFAC). EEMs are recorded at 4.2 K with the aid of a cryogenic fiber-optic probe and a commercial spectrofluorimeter. The simplicity of the experimental procedure and the excellent analytical figures of merit demonstrate the screening potential of this environmentally friendly approach for the routine analysis of numerous coal-tar samples.