title: EDTA titration of calcium and magnesium with a calcium-selective electrode.
abstract: Direct semi-automatic and automatic derivative potentiometric EDTA procedures for the determination of calcium and/or magnesium with a calcium-selective electrode are described. Calcium is titrated in the presence of magnesium at pH 12.0 and the total calcium and magnesium is determined at pH 9.7. Calcium in the range 1-8 mg and magnesium in the range 0.7-5 mg are determined semi-automatically with average errors of about 0.2 and 0.3% respectively and automatically with average errors of 0.4 and 0.7%. Titration times vary from a few seconds to a few minutes.
authors.affiliation: Laboratory of Analytical Chemistry, University of Athens, Athens, Greece.
authors.forename: T P
authors.initials: TP
authors.lastname: Hadjiioannou
authors.forename: D S
authors.initials: DS
authors.lastname: Papastathopoulous