Balogh I S, Maga I M, Hargitai-Tóth A, Andruch V
Department of Chemistry, Uzhorod State University, 12 Pidhirna str., 294000 Uzhorod, Ukraine; Department of Chemistry,College of Nyiregyháza, Sostoi u. 31/B, 4400 Nyiregyháza, Hungary.
Talanta. 2000 Dec 4;53(3):543-9. 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-3N-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 2.5-3.6x10(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(2)SO(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.
采用分光光度法研究了铬（VI）离子与包括1,3,3-三甲基-3N-吲哚啉、苯并恶唑、苯并噻唑和喹啉杂环基团在内的对称花青染料的溶剂萃取。在酸性介质中，在氯离子存在下，可被芳烃和乙酸酯萃取，形成可萃取的铬（VI）离子缔合物。离子缔合物的摩尔吸光系数为2.5 - 3.6×10⁵ l·mol⁻¹·cm⁻¹，具体取决于萃取剂和染料。有色萃取物的吸光度在0.01 - 2.1 mg·l⁻¹范围内符合比尔定律。在0.05 - 0.3 M H₂SO₄的硫酸介质中萃取时，铬的萃取率最高。发现Cr（VI）:Cl:R的摩尔比为1:1:1。研究了一种在各种类型的土壤和掺杂铬（VI）的污水中萃取和分光光度测定铬（VI）的新方法。
