Abstract
Theoretical considerations on the extension of ion exchange method for measuring complex stability constants were made. They are (1) the extension towards lower pH region, making possible to calculate the stability constants of hydrogenated complexes and (2) corrections for the formation of complexes with coexisting substances such as buffer substances. Applying these for the treatments of experimental data on the systems of calcium, strontium, barium and zinc with citrate, stability constants were calculated as listed in Table I.