Identification of the electrophoretic peaks of the phenylthiohydantoin derivatives of amino acids.

Two techniques for identifying the peaks of phenylthiohydantoin (PTH) amino acids separated under the conditions of micellar electrokinetic chromatography were compared. The first technique is linear regression analysis, in which the retention time of an amino acid is a function of the retention times of two retention-time standards. The second technique takes into account hydrophobicity constants log D′, which were calculated using the ACD/LC Simulator 8.0 program package from ACDLabs (Canada). These constants provide an opportunity to calculate the relative migration times of PTH amino acids taking into account the velocity of the electroosmotic flow. The first technique allows us to identify the electrophoretic peaks of all 16 amino acids separated; the second procedure allows us to predict the elution order of the electrophoretic peaks; the use of a correlation equation gives better results. [ABSTRACT FROM AUTHOR]