Spectrophotometric study of the complexation and extraction of chromium(VI) with cyanine dyes

• Published in: Talanta (Oxford) Vol. 53; no. 3; pp. 543 - 549
• Main Authors: Balogh, Ioseph S, Maga, Ivan M, Hargitai-Tóth, Ágnes, Andruch, Vasil
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 04-12-2000; Oxford Elsevier
• Subjects: Analysis methods; Applied sciences; Chromium(VI); Cyanine dye; Exact sciences and technology; Extraction; Natural water pollution; Pollution; Soil and sediments pollution; Spectrophotometry; Water treatment and pollution; Extraction; Chromium(VI); Spectrophotometry; Cyanine dye; Complexation; Absorption spectrometry; Chromium Complexes; Chemical analysis; Chromium VI Ions; Liquid liquid extraction; Reaction mechanism; Water pollution; Transition metal Complexes; Experimental study; Soil pollution
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/S0039-9140(00)00525-7

Solvent extraction of chromium(VI) ion associates with symmetric cyanine dyes including the heterocyclic radicals of 1,3,3-trimethyl-3
N-indoline, benzooxazol, benzothiazol and quinoline has been studied by means of spectrophotometric method. In the acidic medium in the presence of chloride ions, extractable by aromatic hydrocarbons and esters of acetic acids, chromium(VI) ion associates are formed. The molar absorptivities of ion associates are 2.5–3.6×10
5 l mol
−1 cm
−1 in dependence on extractant and dye. The absorbance of the coloured extracts obeys the Beer's law in the range 0.01–2.1 mg l
−1. The extraction of chromium is the highest during extraction from the sulphuric acid medium in the range 0.05–03 M H
2SO
4. It was found that the Cr(VI):Cl:R molar ratio is 1:1:1. A novel procedure of chromium(VI) extraction and spectrophotometric determination in various types of soils and sewage doped with chromium(VI) was examined.