ABSTRACT
A multivariate calibration method (Partial least squares regression, PLS-1), is applied to the simultaneous determination of folic acid (vitamin B0), thiamin (vitamin B1), riboflavin (vitamin B2) and pyridoxal (vitamin B6), in artificial mixtures by ultraviolet/visible absorption spectrophotometry. The concentration ranges used to construct the calibration matrix are 0.4–15.0, 0.7–30, 0.2–11 and 0.8–30 µg mL−1 for vitamin B0, B1, B2 and B6 respectively. The absorption spectrum of the quaternary mixtures is used to perform the optimization of the calibration matrices by the PLS-1 method. for this purpose a cross-validation procedure for estimating the number of principal components in a matrix, is used. Satisfactory recovery values are obtained in most of the quaternary samples analyzed. Mean recovery values for these vitamins are 95–105%.