Improvement of rapid method of quality assessing of sunflower lecithins using the method of nuclear magnetic relaxation
The article presents an improved rapid method of assessing the quality of sunflower lecithins using the method of nuclear magnetic relaxation (NMR). It is established that at a temperature of 23°С with a mass fraction of substances insoluble in acetone, and the sum of the amplitudes of the NMR signals of protons of the third and fourth component (A3 + A4), expressed in percent by Asis, there is a directly proportional linear relationship, which is described by equation (correlation coefficient R2 = 0,9967) of the following form: y = 0,8484x + 7,35. The data on influence of mass of sample of sample of lecithin on the value of the analytical parameter (A3 + A4)/Asis,%, and the measured value of the mass fraction of substances insoluble in acetone, using the method of NMR. It is established that at change of the mass of sample 6 to 14 g, the deviation of the measured values of the mass fraction of substances insoluble in acetone, from a base value did not exceed ± 0,2% abs. It is established that the working temperature range of the NMR-analyzer (from 20 to 30°C) allows to effectively measure the values of the selected analytical parameter, the change in the sample temperature by 1°C leads to a change in the value of the analytical parameter of 0,5% abs.