SIMULTANEOUS DETERMINATION OF IONIZATION-CONSTANTS AND ISOELECTRIC POINTS OF 12 HYDROXY-S-TRIAZINES BY CAPILLARY ZONE ELECTROPHORESIS AND CAPILLARY ISOELECTRIC-FOCUSING

Capillary zone electrophoresis (CZE) was used to separate and determin e simultaneously the pK(1), pK(2), and pI values of 12 environmentally relevant hydroxytriazines (hydroxymetabolites of atrazine, terbuthyla zine, simazine, and propazine and four (arylamino)-s-triazines) and ob serve the effects of the alkylamino and arylamino substituents on the measured values, Capillary isoelectric focusing (CIEF) methods were de veloped to measure the pI of these compounds and compare those values with the CZE-measured pI,s. CZE and CIEF can provide accurate pK and p I values reasonably fast, and pI values measured by the two techniques agree. Knowledge of the pK and pI values of hydroxytriazines is impor tant for an understanding of the binding mechanisms of these molecules in environmental matrices, Because the hydroxytriazines may exist as a myriad of species-neutral, charged, zwitterionic, and keto-enol taut omeric-depending on structure and pH, we briefly addressed the existen ce of these species relative to their electrophoretic analysis.