METHOD OF DETERMINATION OF SULFUR DIOXIDE IN THE PRESENCE OF NITROGEN OXIDES Russian patent published in 1998 - IPC

FIELD: analytical chemistry. SUBSTANCE: gas sample is passed successively through sorption and indicator layers. Mass for sorption layer is prepared by impregnation of silica gel with anthranilic acid spirituous solution and mass for indicator layer is prepared depending on concentrations to be quantitated. At the range 0.001-0.07 g/m³ indicator layer mass is prepared from silica gel treated with solution at pH = 2.4-2.8 containing iodine and starch. At the range 0.01-0.75 g/m³ indicator layer mass is prepared from silica gel treated with solution at pH = 3.4-3.8 containing iodine. Sorption layer absorbs nitrogen oxides and reacted indicator layer mass shows sulfur dioxide concentration in gaseous sample (by layer length with alternated color). Concentration is calculated by tube scale division expressed as mm. Method is used in gaseous analysis in industry. EFFECT: improved method of analysis. 8 tbl