Electrophoretic determination of pK-values of indicators and their relation to colour changes
1Kobe Pharamaceutical Women's College, Nakano 450, Motoyama-cho, Higashi-Nada-Ku, Kobe, Japan.
Abstract:
The pK-values of Xylenol Orange, Pyrocatechol Violet, Thorin and Alizarin Complexone were determined electrophoretically on the basis of the Kiso equation. The colour changes of Xylenol Orange and Alizarin Complexone were found to take place at slightly higher pH values than the electrophoretically determined pK-values. The Kiso-equation for determination of the pK values by electrophoresis yielded reproducible results and the method is useful for complicated substances because the procedure is simple, the equipment inexpensive and only microamounts of the substances are needed.
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