A practical headspace gas chromatographic method for the determination of oxalate in bleaching effluents

This paper reports an improved headspace gas chromatographic (HS-GC) technique for the determination of oxalate content in bleaching effluents. The method is based on the redox reaction between potassium iodate and oxalate, from which the carbon dioxide is generated and measured by HS-GC. The results showed that the reaction in a sulfuric acid solution (0.05 mol/L) was complete in 35 min at 95 °C. The RSD of the method in the repeatability testing was less than 4.5%, the LOQ was 0.35 μg, and the recovery ranged from 95 to 103%. The present method is simpler, more reliable, and more practical compared to the methods reported previously.