Determination of ion exchange degree in zeolites by pulsed 23Na nuclear magnetic resonance

The ion exchange degree in different zeolites was determined indirectly from remaining sodium. The amount of remaining sodium was determined by a measurement of the amplitude of the nuclear magnetization of 23Na from a HNO3 solution of the zeolite by a pulsed NMR method. The degree of ion exchange on zeolites CdX and ZnX was determined with an accuracy to within 5% as compared to polarographic analysis. Owing to its rapidity and simplicity the method is suitable for determination of ion exchange degrees in cases where the presence of sodium or aluminium interferes with a direct analysis of cations, as is the case with zeolites of alkali metals