METHOD OF DETERMINING TOTAL SULFUR LEVEL IN ORGANIC MATERIAL Russian patent published in 2003 - IPC

FIELD: analytical methods. SUBSTANCE: invention provides analytically controlling total sulfur level basically in tall colophony, including modified one, in tall sand as well as in its products: pectol, pectic concentrate (mixture of tall sand with deciduous tall oil and liquid tall oil rectification products). Method consists in burning weighed quantity of initial organic material in presence of magnesium oxide and sodium carbonate at their weight ratio between 3:1 and 12:1 to form sodium sulfite. Product is dissolved in water. Precipitate is filtered off and washed. Sodium sulfite-containing filtrate is treated with hydrogen peroxide at pH 1-3 to form sulfate ions, which are then bound by barium chloride. The latter operation is carried out by forming suspension, which is obtained by mixing (i) 4-6% barium chloride aqueous solution stabilized by ethylene glycol/ethanol mixture at barium chloride solution/ethylene glycol/ethanol volume ratio 1:3:3 with (ii) hydrogen peroxide-treated filtrate. After that, searched value is found with the aid of photocolorimetric analysis of suspension followed by measuring concentration of sulfate ions using calibration graph: content of sulfate ions plotted vs. optical density. Thus obtained value is then converted into total sulfur content. EFFECT: accelerated analytical procedure and increased analytical accuracy. 3 cl, 3 ex