SYNTHESIS AND STUDY OF DIMETHYLPOLYSULFIDES AS REFERENCE MATERIALS FOR WATER ANALYSIS

摘要

In-house reference materials (IHRMs) for determination of inorganic polysulfides in water have been developed. The determination is based on the polysulfides' derivatization with a methylation agent followed by GC/MS or HPLC analysis of the difunctionalized polysulfides. Therefore, the IHRMs are synthesized in the form of dimethylated polysulfides containing from four to eight atoms of sulfur. The composition of the compounds is confirmed by NMR and by the fact of the dependence of the dimethylpolysulfide retention time in HPLC on the number of sulfur atoms in the molecule. Stability of the IHRMs at -20 and +5°C is studied by HPLC with UV detector at 230 nm. The total sulfur content is controlled by the IHRMs' oxidation with perchloric acid in high-pressure vessels (bombes) followed by determination of the formed sulfate using ICP.