METHOD OF ASSESSING METHYL ALCOHOL IN WATER Russian patent published in 2001 - IPC

FIELD: analytical methods. SUBSTANCE: preliminarily, a part of sample is distilled off in presence of alkali and two distillate portions are sampled. The two portions are treated with sulfuric acid at heating on boiling water bath for 5-7 min, after which one portion is consecutively treated with solutions of potassium permanganate, sodium sulfite, chromotrope acid, and concentrated sulfuric acid, whereas the second portion is treated with chromotrope acid solution and concentrated sulfuric acid. Concentration of methanol is calculated from results of photometric measurements of solutions of the two sample portions taking into account coefficient reflecting multiplicity of decrease of formaldehyde concentration during treatment of the first sample portion. EFFECT: increased measurement accuracy. 2 cl, 4 ex