Soy lecithin Pharma Grade

[Identification] 　 (1) Take 0.1g of this product, put it in a crucible, add 3g of sodium carbonate-potassium carbonate (2:1), mix well, heat with a slight fire, and the generated gas can make the wet red litmus test paper blue.
(2) Take about 100mg of the residue left under the identification (1), and slowly burn until all the carbonized materials disappear, cool, add 30ml of water, dissolve the residue with slight heat, filter, put the filtrate in a test tube, and add sulfuric acid dropwise without bubbles Produce, add 4 drops of sulfuric acid, add a little ammonium molybdate, heating, it should be yellow-green.
[Check] 　 Preparation of free fatty acid 　 Reference substance solution 　 Weigh 0.512g of palmitic acid and place it in a 50ml measuring bottle.
Dissolve with n-heptane and dilute to the mark, shake well, take 2ml accurately, place in a 50ml measuring flask, and dilute to the mark with n-heptane.
Preparation of test solution 　 Take about 1g of this product, accurately weigh it, put it in a 25ml measuring bottle, dissolve with isopropanol and dilute to the mark, that is, you get it. More: https://www.51240.com/
The measuring method is to accurately measure 1ml each of the test solution and the reference solution, and put them in 20ml test tubes with plugs respectively, and add isopropyl alcohol-n-heptane-0.5mol/L sulfuric acid solution (40:10:1) mixed solution 5.0 ml, shake for 1 minute, and leave for 10 minutes.
For the test product solution tube, add 3 ml of n-heptane and 3 ml of water accurately, and for the reference sample solution tube, add 2 ml of n-heptane and 4 ml of water. From the "plug", determine according to the method of free fatty acid in the fat emulsion injection. The number of milliliters of sodium hydroxide titrant (0.01mol/L) consumed by the test solution shall not be greater than the number of milliliters of sodium hydroxide titrant (0.01mol/L) consumed by the reference substance solution.
Saponification value 　 should be 195 ~ 212 (Chinese Pharmacopoeia 1995 edition two appendix Ⅶ　H).
The iodine value should be 65-73 (Chinese Pharmacopoeia 1995 edition appendix Ⅶ　H).
[Determination of content] 　Nitrogen is about 2.5g of this product, and it is determined according to the law (Chinese Pharmacopoeia 1995 edition appendix Ⅶ　D first method).
Preparation of Phosphorus Reference Standard Solution Take 105°C and dry to a constant weight of about 0.13g of potassium dihydrogen phosphate. Weigh it accurately. Place it in a 100ml measuring bottle, add water to dissolve and dilute to the mark. Take a precise amount of 10ml and place it in a 100ml measuring bottle. Dilute to the mark, shake well, containing about 30μg of phosphorus (P) per 1ml.
For the preparation of the test solution, take about 0.1g of this product, accurately weigh it, place it in a crucible, add 2ml of chloroform to dissolve, add 2g of zinc oxide, distill off the chloroform, slowly burn to carbonize the sample, then burn at 600 ℃ 1 Hours, let cool, add 10ml of hydrochloric acid solution (1→2), boil for 5 minutes to dissolve the residue, transfer to a 100ml volumetric flask, and dilute to the mark with water.