SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF FOLIC ACID, THIAMIN, RIBOFLAVIN, AND PYRIDOXAL USING PARTIAL LEAST-SQUARES REGRESSION METHOD

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%.

Keywords:

• Simultaneous analysis
• Folic acid
• Thiamin
• Riboflavin
• Pyridoxal
• Partial least squares

Acknowledgments