Development and Validation of a Rapid Chemometrics-Assisted Spectrophotometry and Liquid Chromatography Methods for the Simultaneous Determination of the Phenylalanine, Tryptophan and Tyrosine in the Pharmaceutical Products

The simultaneous multicomponent analysis is usually carried out using multivariate calibration models, such as the partial least squares (PLS). The genetic algorithm (GA) is a suitable method for the wavelength selection for the PLS calibration of the mixtures with almost identical spectra and without loss of the predictive ability, using the spectrophotometric method. In this work, a simple and precise method for rapid and accurate simultaneous determination of phenylalanine, tryptophan and tyrosine is proposed with the employment of the PLS regression together with GA for the variable selection. The method was successfully applied to the quantitation of these amino acids in aminoplasmal serum, providing results in agreement with those obtained by high performance liquid chromatography (HPLC).