USE OF GLASS ELECTRODE IN DEUTERIUM OXIDE AND RELATION BETWEEN STANDARDIZED PD (PAD) SCALE AND OPERATIONAL PH IN HEAVY WATER

Commercial glass electrodes have been compared both directly and indirectly with the deuterium gas electrode at 25° C in buffered solutions of pD from 1 to 13. It is confirmed that the glass electrode functions as well in heavy water as in ordinary water. The relation between the operational pH of a buffer solution in heavy water (obtained with a glass electrode stanardized in an ordinary water buffer solution) and its pD or pad value obtained from measurements on cells without liquid junction has been examined and correction factors determined for both glass and gas electrodes. The operational pH of buffer solutions in heavy water at 25° C, measured with the glass electrode, can be converted into a pD value by adding 0.41 (molar scale) or 0.45 (molal scale) for 2 < pD < 9. © 1968, American Chemical Society. All rights reserved.