Preservation and Simultaneous Analysis of Relevant Soluble Sulfur Species in Sewage Samples

An ion chromatographic method for the simultaneous determination of sulfide, sulfite, sulfate and thiosulfate in wastewater samples has been developed. The samples are preserved with a special sulfide anti-oxidant buffer (SAOB) that allows storing the samples for at least four days at 4 DC without significant deterioration of the different sulfur species. The study demonstrates the extreme importance of a careful sample handling and preservation procedure for these samples as oxidation with air and volatilisation of hydrogen sulfide can severely impact upon the accuracy of the analytical results. The benefits of accurately analysing all of the relevant soluble sulfur species in a single, fully automated method outweigh the increased costs of the method compared to traditional spectrophotometric methods