Determination of hexacyanoferrates based on the diacetone–BrO3––Mn(II)–H2SO4 chemical oscillatory reaction

Abstract

A new method for the determination of hexacyanoferrates in an oscillating chemical system involving the Mn(II)-catalysed reaction between diacetone and potassium bromate in an acidic medium is proposed. The best reaction conditions and reactant concentrations are reported. The method relies on the linear relationship between the changes in the oscillation period of the chemical system and the concentration of hexacyanoferrates in the range 1.0 × 10^–7–3.3 × 10^–5 mol dm^–3. The relative standard deviation for 4 × 10^–6 mol dm^–3 Fe(CN)₆^3– is 2.0% (n = 6). The possible mechanism of this reaction is discussed.