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By use of a capillary electrophoretic method for anion analysis the anodic oxidation of thiosulfate, present in color photo bleach-fix solutions, was investigated. In a specially constructed electrolysis cell with a cation-exchange membrane separating the electrode chambers and with a carbon flow-through three-dimensional anode the two-stage anodic oxidation of S

Ion-pair chromatographic technique was developed for the rapid and simple determination of the main contaminants (bromide, iodide, sulphite, thiosulphate, thiocyanate, iron(III)-EDTA chelate, free EDTA, hydroquinone and phenidone) in spent photographic solutions. Free EDTA was converted into stable Ni(II)-EDTA chelate prior to analysis. The optimal mobile phase conditions were established by varying the concentrations of tetrabutylammonium (TBA) phosphate and acetonitrile, pH and ionic strength. Separation of five inorganic anions, two metal chelates and two neutral compounds was accomplished in about 30 min using a mobile phase containing 7.5 mmol/L TBA-phosphate, 10 mmol/L NaCl (pH 6.5) and 20% (v/v) acetonitrile. The detection limits (UV detection at 210 nm) ranged from 0.4 µmol/L for phenidone to 8 µmol/L for sulphite with a linearity of 2-2.5 orders of magnitude. The method was applied to the rapid monitoring of spent photographic solutions before and after decomposition. The recovery tests established for two samples were within the range 95-103%.