ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Indirect Extraction-Spectrophotometric Determination of Chromium

M. Telepčáková, V. Andruch, and I. S. Balogh

Department of Physical and Analytical Chemistry, Faculty of Natural Sciences, P. J. Šafárik University, Sk-041 54 Košice

E-mail: monikat@pobox.sk

Received: 12 December 2002

Abstract: An analytical procedure for the indirect spectropimtometric determination of trace amounts of hexavalent chromium in a model sample of water has been developed. Chromium in its hexavalent state is reduced to its trivalent state in the presence of an excess of iodide ion in an acidic medium. The liberated triiodide ion forms with a cationic dye ion associate which is extracted into toluene. The extraction of chromium(Vl) is the highest from a 0.08 mol dm^-3 sulfuric acid medium. The intensively coloured complex absorbs at λ = 430 nm. The system obeys Beer's law in the concentration range up to 2 mg dm^-3. Corresponding limit of detection (based on 3o) is 0.234 mg dm^-3 Cr(VI).

Full paper in Portable Document Format: 592a109.pdf

Chemical Papers 59 (2) 109–112 (2005)