Surfactant Extraction and Determination of Ruthenium(III) as a Thiocyanato Complex

Ruthenium(III) was reacted to form a complex with thiocyanate, and extracted into the surfactant phase with Zephiramine (Z) by heating. The structure of this ion-pair was estimated to be [RuX2(SCN)2]−·Z+, in which X was a chloride ion, and was observed to cause an increasing absorbance and a blue shift of the spectrum. The determination of ruthenium(III) was investigated by the surfactant extraction-spectrophotometric method using a nonionic surfactant of Triton X-100 as an extraction solvent. The molar absorptivity was equal to 1.16 × 104 dm3 cm−1 mol−1 at 565 nm. Ruthenium(III) could be concentrated from the solution into a surfactant phase having a small volume. The first-order derivative spectroscopic method was used to reduce the interference from other platinum-group elements, such as osmium.