Calcium lactate - Determination

To about 0.3g, accurately weighed, add water 100ml, heated to dissolve,
 Sodium lactate, add sodium hydroxide solution 15ml with calcium purpurin indicator about 0.1g, with ethylene diamine tetra-acetic acid disodium titrant (0.05 mol / L) titration until the solution changes from purple to pure blue. Each 1ml of ethylene diamine tetra acetic acid disodium titrant (0.05mol / L) is equivalent to 15.42mg of C6H10CaO6 · 5H2O. Slightly hazardous for water Do not allow undiluted product or large quantities of it to reach ground water, water course or magnessium lactate, without proper governmental permits do not allow material to be released to the environment.