Multivariate Characterization of Amino Acids by Reversed Phase High Pressure Liquid Chromatography

The twenty coded and four non coded amino acids were multivariately characterized by HPLC. The retention times for dansyl derivatives of the amino acids in nine eluents on a reversed phase C18 column were used. With the nine HPLC variables and five additional variables (molecular weight, pK‐COOH, pK‐NH2, pI and substituent van der Waals volume) comprizing the matrix X, two partial least squares projections to latent structures (PLS) models were developed for eighteen of the coded amino acids, with the previously developed principal properties (PP.s) z1 and z2 as single y‐variables. The PLS models described 90% and 87% of variance in z1 and z2 respectively. Values for z1 and z2 for the four non coded amino acids were predicted from their X‐data and the PLS models.