Extraction-Spectrophotometric Determination of Ruthenium(III) with O, O′-Diethyl Dithiophosphate1

Abstract

Ruthenium(III) reacted with O, O′-diethyl dithiophosphate(dtp^-) in a hot hydrochloric acid solution and gave a red complex, [Ru(dtp)₃], which could be extracted into chloroform. The spectrum of the extracted complex was affected by experimental conditions such as reaction temperature, reaction time, hydrochloric acid concentration and dtp^- concentration. The calibration graph for ruthenium(III) was linear over the range of (0.17-5.2)×10^-4mol dm^-3 ruthenium(III) under the condition of 6mol dm^-3 hydrochloric acid, 0.1mol dm^-3 dtp^- and heating at 60°C for 15min. The molar absorptivity at 510nm was 2.18×10³cm^-1 mol^-1 dm³ and the relative standard deviation was 1.5% (12runs) for 3.5×10^-4mol dm^-3 ruthenium. The ions which interfered severely were Mo(VI), Cu(II), Pb(II), Bi(III), Tl(I), In(III), Te(IV), Cd(II), V(V), Hg(II), Ag(I), Co(II) and NO₂^-.