METHOD OF DETERMINING RIBOFLAVIN IN AQUEOUS SOLUTION Russian patent published in 2010 - IPC G01N31/00 G01N33/00 B01D11/00 

FIELD: chemistry.

SUBSTANCE: water-salt solution of riboflavin is prepared, for which a riboflavin sample weighing 1 mg is put into a 100 cm³ measuring flask, 50 cm³ distilled water is added and the sample dissolved while stirring, 40 g ammonium sulphate is added to the obtained solution and brought to the saturation mark with ammonium sulphate solution while stirring, riboflavin is extracted with chemically pure acetone, for which acetone is added to the obtained solution in volume ratio of the water-salt solution of riboflavin to acetone equal 5:1, extraction is carried out until establishment of interphase equilibrium in 5-7 minutes, after stratification, the aqueous phase system is separated from the organic phase and analysed through UV spectrometry, a calibration curve of optical density of the water-salt solution versus concentration of riboflavin is plotted, optical density of the water-salt solution is measured on a UV spectrophotometre at wavelength 445 nm, concentration of riboflavin in the aqueous solution is determined from the calibrated curve, riboflavin is again extracted from the water-salt solution in the same conditions, the aqueous phase is separated and content of riboflavin is determined via UV spectrometry.

EFFECT: more reliable analysis.

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