title: Simultaneous Determination of Ionization Constants and Isoelectric Points of 12 Hydroxy-s-Triazines by Capillary Zone Electrophoresis and Capillary Isoelectric Focusing.
abstract: Capillary zone electrophoresis (CZE) was used to separate and determine simultaneously the pK(1), pK(2), and pI values of 12 environmentally relevant hydroxytriazines (hydroxymetabolites of atrazine, terbuthylazine, simazine, and propazine and four (arylamino)-s-triazines) and observe the effects of the alkylamino and arylamino substituents on the measured values. Capillary isoelectric focusing (CIEF) methods were developed 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 pI values reasonably fast, and pI values measured by the two techniques agree. Knowledge of the pK and pI values of hydroxytriazines is important for an understanding of the binding mechanisms of these molecules in environmental matrices. Because the hydroxytriazines may exist as a myriad of species [Formula: see text] neutral, charged, zwitterionic, and keto-enol tautomeric [Formula: see text] depending on structure and pH, we briefly addressed the existence of these species relative to their electrophoretic analysis.
authors.affiliation: National Research Council and National Exposure Research Laboratory, U.S. Environmental Protection Agency, 960 College Station Road, Athens, Georgia 30605-2720, and GSF-Forschungszentrum für Umwelt und Gesundheit GmbH, Institut für Ökologische Chemie, Schulstrasse 10, D-85356 Freising-Attaching, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Schmitt
authors.forename: T
authors.initials: T
authors.lastname: Poiger
authors.forename: R
authors.initials: R
authors.lastname: Simon
authors.forename: D
authors.initials: D
authors.lastname: Freitag
authors.forename: A
authors.initials: A
authors.lastname: Kettrup
authors.forename: A W
authors.initials: AW
authors.lastname: Garrison