Application of PARAFAC for calibration with excitation-emission matrix fluorescence spectra of three classes of environmental pollutants

Parallel factor analysis (PARAFAC) is applied to three calibrations of a field-portable, cuvette-based, single-measurement, excitation–emission matrix fluorometer. In the first example the fluorometer is calibrated based on interactions between a non-fluorescent DDT-type pesticide and a fluorescent dye. PARAFAC is employed to deconvolve the fluorescence profiles of dissociated and complexed dye states. Calibration is performed based on the intensity of dye–pesticide fluorescence. In the second example, weighted PARAFAC (W-PARAFAC) is applied to determination of three polynuclear aromatic hydrocarbons (PAHs). The weighted algorithm is required to incorporate saturated channels of the CCD detector into the calibration model. In the third example, W-PARAFAC is applied to calibration of two carbamate pesticides. The weighted algorithm is required to account for Rayleigh and Raman scattering overlapping with the fluorescence spectra. For theses three applications, parts-per-trillion to parts-per-billion detection limits are observed in aqueous solutions.