Determination of para-aminobenzoic acid (PABA) in B-complex tablets using the Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) method

The para-aminobenzoic acid (paba) product is an amphoteric component that has three formsin an aqueous solution. paba can titrate with strong acid or a strong base. the conjugated acid of paba canionize in two sections, and two peaks can be detected to overlap. in this situation, the correct resolutionand quantitation of the analytes is not possible, an uv spectrophotometric acid-base titrations method isproposed for the quantitative determination of paba products in pharmaceutical samples. the acid-baseequilibrium model is included in the multivariate curve resolution-alternating least squares (mcr-als)method. this method makes data evaluation possible, even when spectra of contributing substances arehighly overlapping or reaction intermediates have to be detected. furthermore, quantification of analytesis possible in the presence of unknown interferents if pure analyte standards are available. the resultsobtained indicate a recovery of > 91% and relative error of < 9% in the proposed approach for the pabaproduct