Determination of carbendazim, fuberidazole and thiabendazole by three-dimensional excitation-emission matrix fluorescence and parallel factor analysis

We simultaneously determined carbendazim, fuberidazole and thiabendazole by excitation-emission matrix (EEM) fluorescence in combination with parallel factor analysis (PARAFAC). Three-way deconvolution provided the pure analyte spectra from which we estimated the selectivity and sensitivity of the pesticides, and the relative concentration in the mixtures from which we established a linear calibration. Special attention was given calculating such figures of merit as precision, sensitivity and limit of detection (LOD), derived from the univariate calibration curve. The method, which had a relative precision of around 2-3% for the three pesticides, provided limits of detection of 20 ng ml⁻¹ for carbendazim, 4.7 ng ml⁻¹ for thiabendazole and 0.15 ng ml⁻¹ for fuberidazole. The accuracy of the method, evaluated through the root mean square error of prediction (RMSEP), was 27.5, 1.4, and 0.03 ng ml⁻¹, respectively, for each of the pesticides.