Collect. Czech. Chem. Commun.
1991, 56, 1850-1855
https://doi.org/10.1135/cccc19911850
Standardization of dilute solutions of EDTA by photometric titration with standard tetraamminecopper(II) titrant
Vladimír Mach, Stanislav Kotrlý and Václav Říha
Department of Analytical Chemistry, Institute of Chemical Technology, 532 10 Pardubice
Abstract
Direct photometric titration (without an added indicator) using a standard ammoniacal solution of copper(II) prepared from pure copper metal asa primary standard is recommended as a reliable method for the standardization of Na2H2(edta) in 10-3 -5 . 10-4M solutions. The technique of photometric microtitration (720 nm, 50 mm cell) with an increased precision of transmittance reading (s ~10-2%, n > 7) and in optimum medium of pH 4.7 ± 0.4 (acetate buffer) can yield precise results in assays of EDTA (sr ⪬ 10-1%, n = 6-9).