Fast and accurate alternative UV-chemometric method for the determination of chlorophyll A and B in broccoli (Brassica oleracea Italica) and cabbage (Brassica oleracea Sabauda) plants

The aim of this work was to establish a multivariate method for the rapid quantification of chlorophyll A and B in broccoli and cabbage plants using photometric signals. A partial least squares (PLS) model was optimized using the UV spectra of a set of calibration samples. Limit of detection (0.174 and 0.304 mu g mL(-1) for chlorophyll A and B respectively), selectivity (0.946 and 0.942 respectively) and sensitivity (0.0324 and 0.0183 absorbance mL mu g(-1) respectively) were calculated in order to establish the robustness of the proposed methodology. After method validation, the PLS model was applied to determine the concentration of both pigments in different broccoli and cabbage plants. The concentrations of these pigments, calculated by the optimized chemometric method, were compared with those obtained by a chromatographic and photometric method based on the absorbance of sample at two different wavelengths. The accuracy of our results was comparable with that of results obtained by a chromatographic method improving significantly the accuracy compared with that of previously reported photometric approaches. (C) 2010 Elsevier Inc. All rights reserved.