Spectrophotometric estimation of rhenium with 5-chloro-2-hydroxythiobenzhydrazide after its extraction separation using n-octylaniline

• Published in: Talanta (Oxford) Vol. 43; no. 12; pp. 2137 - 2142
• Main Authors: Sawant, S.S., Anuse, M.A., Chavan, M.B.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.1996; Oxford Elsevier
• Subjects: 5-Chloro-2-hydroxythiobenzhydrazide; Analytical chemistry; Applied sciences; Chemistry; Exact sciences and technology; Extraction separation; Metals. Metallurgy; n-Octylaniline; Rhenium; Spectrometric and optical methods; 5-Chloro-2-hydroxythiobenzhydrazide; Rhenium; Extraction separation; n-Octylaniline; Trace analysis; Organic hydrazide; Chemical analysis; Synthetic medium; Liquid liquid extraction; Ultraviolet spectroscopy; Alloys; Metal complex; Spectrophotometry; Chemical enrichment
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/S0039-9140(96)02001-2

A solution of n-octylaniline in chloroform extracts rhenium selectively from 0.12–0.16 M nitric acid medium. Rhenium from the organic phase is backstripped with 5% aqueous ammonia solution and estimated spectrophotometrically with 5-chloro-2-hydroxythiobenzhydrazide (5-Cl-2-OHTBH). 5-Cl-2-OHTBH forms a blue complex with rhenium on heating in the acidity range 0.40–3.5 M HCl. The complex is extracted into chloroform and its absorbance is measured at 580 nm. The complex is stable for more than 12 h with a molar extinction coefficient of 9.0 × 10 3l mole −1 cm −1 and a Sandell sensitivity of 0.019 μg cm 2.