Simultaneous determination of five triarylmethane colorants in syrup by applying multivariate curve resolution to second-derivative visible absorption spectra

A method for the simultaneous determination of five triarylmethane colorants (brilliant blue FCF, patent blue V, patent blue VF, fast green FCF, and green S) in syrup samples was proposed by applying multivariate curve resolution to second-derivative visible absorption spectra in citrate and carbonate buffer solutions. Even for heavily overlapping spectra, adopting second-derivative spectra and multiway analysis in citrate and carbonate buffer solutions enhanced specificity for the analytes and achieved prediction performance with a coefficient of determination ( R 2 ) > 0.90, root mean square error of prediction (RMSEP) < 0.20 mg/L, and limit of detection (LOD) < 0.50 mg/L for all five analytes. The basis set expansion method succeeded in a reasonable estimation of the second-derivative spectra with the interferant. For commercial syrup samples, the present method predicted results without significant differences compared to the results measured using liquid chromatography-mass spectrometry. The proposed method provides a rapid alternative to liquid chromatography techniques for the quantification of multiple colorants in food samples. Graphical Abstract