Four-way modeling of 4.2 K time-resolved excitation emission fluorescence data for the quantitation of polycyclic aromatic hydrocarbons in soil samples

• Published in: Talanta (Oxford) 2012-11, Vol.101, p.330-336
• Main Authors: GOICOECHEA, Hector C, SHENJIANG YU, MOORE, Anthony F. T, CAMPIGLIA, Andres D
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Arrays; Chemistry; Chromatography, High Pressure Liquid; Cost analysis; Exact sciences and technology; Excitation; Fluorescence; Models, Theoretical; Polycyclic aromatic hydrocarbons; Polycyclic Compounds - analysis; Screening; Soil (material); Soil Pollutants - analysis; Spectrometric and optical methods; Windows (intervals)
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2012.09.035

A screening method for the soil analysis of 15 Environmental Protection Agency-polycyclic aromatic hydrocarbons (EPA-PAHs) is reported. The new method is based on the collection of 4.2 K fluorescence time-resolved excitation-emission cubes (TREECs) via laser-excited time-resolved Shpol'skii spectroscopy. 4.2 K fluorescence TREECs result from the superposition of fluorescence time-resolved excitation emission matrices recorded at different time windows from the laser excitation pulse. Potential interference from unknown sample concomitants is handled by processing the four-way 4.2 K fluorescence TREEC data arrays with either parallel factor analysis (PARAFAC) or unfolded partial least-squares/residual-trilinearization(U-PLS/RTL). The sensitivity of the two approaches makes possible to determine PAHs at the ng g(-1) to pg g(-1) concentration level with no need for sample pre-concentration. Its selectivity eliminates sample clean-up steps and chromatographic separation. These features reduce PAH loss, analysis time and cost. The method is environmentally friendly as the complete screening of the 15 EPA-PAHs takes only 250 μL of organic solvent per sample.