Liquid%liquid extraction of a rhenium%thiocyanate complex with hexamethylphosphoramide and direct spectrophotometric determination in the organic phase.
A sensitive and selective method for the extraction of trace rhenium is based on extraction of a Re-thiocyanate complex with hexamethylphosphoramide and chloroform at an acidity of 2-3 M hydrochloric acid. Hydrazine sulphate is used as the reducing agent. The system obeys Beer's law at 430 nm, the optimum concentration range is 1.7-8 ppm. The molar absorptivity is calculated to be 2.23 x 10(4) 1.mole(-1) .cm(-1). The colour is stable for at least 48 hr. The method is simple and rapid and is generally free from interference by most of the metals commonly associated with rhenium.
Mitra
M
M
Department of Chemistry, Jadavpur University, Calcutta-700032, India.
Mitra
B K
BK