METHOD OF DETERMINING ACID VALUE OF LIQUID SOYA BEAN LECITHIN Russian patent published in 2020 - IPC G01N24/08 

FIELD: chemistry.

SUBSTANCE: invention relates to analytical chemistry, specifically to practical application of nuclear magnetic resonance (NMR) method for determination of acid number (An) of liquid soya lecithin and can be used in fat-and-oil industry. Method for determining acid number of liquid soya lecithin involves sampling liquid soya lecithin, successive mixing of the sample with carbon tetrachloride and aqueous sodium hydroxide solution with concentration of 0.9-1.1 mol/dm³ to obtain a mixture, placing the obtained mixture into a pulse NMR analyzer, measuring the amplitude of nuclear-magnetic relaxation signals of protons of the formed soap (A_m) and calculating the acid value by equation, wherein mixing of liquid soya bean lecithin with carbon tetrachloride is carried out at a weight ratio of liquid soya lecithin - tetrachloromethane of carbon equal to (1:3)÷(1:3.5), and mixing aqueous solution of sodium hydroxide is carried out at a weight ratio of liquid soya bean lecithin - aqueous solution of sodium hydroxide, equal to (1:0.5)÷(1:0.6), wherein to calculate the acid number value, an equation is used: An = 7.1283+0.7908⋅A_m.

EFFECT: technical result is higher accuracy of analysis results.

1 cl, 1 tbl, 1 dwg