Calcium stearate is commonly used as a food additive. In this case, if the content of calcium stearate is too much, it will cause food additives to exceed the standard, which is not allowed by the regulation. Then, we need to measure to know whether the amount of calcium stearate is excessive. How is the calcium stearate content measured?
1. Accurately weigh about 1.2g of the sample, add 50mL of hydrochloric acid solution with a concentration of 0.1mol/L, boil for 10min, or clarify to the fatty acid layer, and add water to maintain the original volume if necessary.
2. Cool, filter, wash the filtrate and flask thoroughly with water, the resulting lotion is no longer acidic to litmus.
3. The filtrate with 1mol/L sodium hydroxide test solution neutralization to litmus neutral.
4. Under full stirring by magnetic stirrer, add about 30mL of 0.05mol/L EDTA disodium solution through a 50mL buret, then add 15mL of 1mol/L sodium hydroxide test solution and 300mg of hydroxynaphthol blue indicator, and continue titration to the blue end point.
5. EDTA disodium solution of 0.05mol/L is equivalent to CaO2.804mg per ml. In the determination of calcium stearate content, the key place is that these data can not be wrong, can! If you can't measure the amount of calcium stearate, you can contact our technical staff for help!