4-(2'-Furalideneimino)-3-Methyl-5-Mercapto-1,2,4- Triazole as a Selective Reagentfor Extractive Spectrophotometric Determination of Rhodium (III)

摘要

The colour reaction of 4-(2'fiiralideneimino)-3-methyl-5-mercapto-1,2,4- triazole (FIMMT) with rhodium(III) was studied systematically. Rhodium (III) forms (1:2) yellow complex with FIMMT in a HOAc-NaOAc buffer solution at pH 5.4 after heating in boiling water bath for 6 min. The absorbance of the extracted rhodium (III) -FIMMT complex in n-butanol was measured at 410 nra against reagent blank. The optimum conditions for full colour development were studied. The Beer's law obeyed in the concentration range of 10.5-36.0 ppm. The molar absorptivity and Sandell's sensitivity were calculated to be2. lxlO3 Lmcl1 cm1 and0.051 igcm1 respectively. Interference of large number ofanions and cations was studied. Thecationic interferences were removed by masking with EDTA and tartrate. The method has been applied for the determination of rhodium(III) in synthetic mixtures containing other platinum group metals which are commonly associated with it.