Improved method for spectrophotometric determination of ruthenium using 1,10-phenanthroline: application for analysis of complex compounds

Abstract

Spectrophotometric determination of ruthenium using 1,10-phenanthroline was modified and used for quantification of the ruthenium content in complexes. Complexes were decomposed by using aqua regia and a full recovery of ruthenium from thus obtained solutions was observed at pH 6 after three hours of heating at 90 °C with a hundredfold excess of phenanthroline. The modified procedure has several important advantages compared to the originally reported procedure. It is faster and more accessible for laboratory practice since it does not require tedious RuO₄ distillation. Also it has much wider linearity range (20 μg L⁻¹ to 12 mg L⁻¹ compared to 162 μg L⁻¹ to 1.62 mg L⁻¹) and lower limit of quantification (30.4 μg L⁻¹ compared to 100 μg L⁻¹). Moreover, recoveries of ruthenium are practically quantitative and the single standard addition method, instead of the calibration curve method, can be successfully used for accurate analysis.