Can I read Retention of ionizable compounds on HPLC. 6. pH measurements with the glass electrode in methanol–water mixtures on EtoBox?

Retention of ionizable compounds on HPLC. 6. pH measurements with the glass electrode in methanol–water mixtures by Immaculada Canals; Fadoua Z. Oumada; Martı́ Rosés; Elisabeth Bosch is a Chemistry article available to read on EtoBox.

What is Retention of ionizable compounds on HPLC. 6. pH measurements with the glass electrode in methanol–water mixtures about?

The relationship, delta values, between the two rigorous pH scales, S(S)pH (pH measured in a methanol-water mixture and referred to the same mixture as standard state) and S(W)pH (pH measured in a methanol-water mixture but referred to water as standard state), in several methanol-water mixtures was determined (delta = S(W)pH-S(S)pH). Delta values were measured using a combined glass electrode and a wide set of buffer solutions. The results are consistent with those obtained with the hydrogen electrode. This confirms the aptness of the glass electrode to achieve rigorous pH measurements in methanol-water mixtures. An equation that relates delta and composition of methanol-water mixtures, and allows delta computation at any composition by interpolation, is proposed. Therefore, S(S)pH can be achieved from the experimental S(W)pH value and delta at any mobile phase composition. S(S)pH (or S(W)pH) values are related to the chromatographic retention of ionizable compounds through their thermodynamic acid-base constants in the methanol-water mixture used as mobile phase. These relationships were tested for the retention variation of several acids and bases with the pH of the mobile phase

Who reads Retention of ionizable compounds on HPLC. 6. pH measurements with the glass electrode in methanol–water mixtures?

Author

Immaculada Canals; Fadoua Z. Oumada; Martı́ Rosés; Elisabeth Bosch

Publisher

Elsevier Science; Elsevier ; Elsevier BV (ISSN 1873-3778)

Published

2001

Language

EN

Field

Chemistry (Physical Sciences)