Excitation-emission matrix fluorescence based determination of carbamate pesticides and polycyclic aromatic hydrocarbons

The ability to accurately quantitate trace pesticides and polycyclic aromat ic hydrocarbons (PAHs) by excitation-emission matrix (EEM) fluorescence spe ctroscopy, when coupled with parallel factor analysis (PARAFAC) deconvoluti on of the EEM spectra, is demonstrated and discussed. Two EEM fluorometers were investigated. One fluorometer, using a cuvette cell sample holder, rea lized limits of detection of 1.1, 6.6, and 13 ppb for I-naphthol, carbaryl, and carbofuran in methanol mixtures, respectively. 0.2 ppb limits of detec tion were also observed for three PAHs. With this fluorometer, the PARAFAC model was employed to resolve the analyte spectra from overlapping fluoresc ence signals and Raman scattering profiles. Employing a second fluorometer with a fiber-optic probe for remote sampling yielded 10-30 ppb limits of de tection for 9 PAHs. The PARAFAC model was required here to resolve the PAH spectra from the instrumental background. (C) 1999 Elsevier Science B.V. Al l rights reserved.