| Method of analysis for Lactic Acid IP |
| 1.0 PROCEDURE 1.1 Sampling and Handling 1.1.1 Quantity for composite sample for analysis Lactic acid molecular weight: 90.078 For chemical analysis: 120gm 1.1.2 Control Sample of lactic acid For chemical analysis: 2 x 120gm 1.1.3 Reanalysis Period Two year. 1.2 Physical and Chemical Testing 1.2.1 Description Colourless or slightly yellow, viscous liquid; almost odourless; hygroscopic 1.2.2 Solubility Miscible in all proportions with water, with ethanol (95%) and with ether. 1.2.3 Citric, oxalic and phosphoric acids: To 5 ml of the solution prepared in the test for Heavy metals add 6M ammonia until slightly alkaline. Add 1 ml of calcium chloride solution and heat on a water-bath for 5 minutes. Both before and after heating, any opalescence in the solution is not more intense than that in a mixture of 5 ml of the test solution and 1 ml of water. To read this GTP click here Method of analysis of Sodium Hydroxide. 1.2.4 Ether-insoluble substances Dissolve 1.0 g in 25 ml of ether; the solution is not more opalescent than the solvent used for the test. 1.2.5 Volatile fatty acids: Cautiously heat 5 g in a glass-stoppered flask at 50o for 10 minutes; no unpleasant odour resembling that of the lower fatty acids is recognizable immediately after opening the flask. 1.2.6 Assay of Lactic acid Take 1.0 gm. in glass- stoppered flask and add 10 millilitre of purified water/water for injection. Add 20.0 millilitre of 1M sodium hydroxide, stopper the flask and allow to stand for 30 minutes. Titrate the excess of alkali with 1M hydrochloric acid using dilute phenolphthalein solution as indicator until the pink colour is discharged. Each ml of 1M sodium hydroxide is equivalent to 0.09008 g of C3H6O3. Calculation: % Assay = Burette reading X Molarity of HCl X 0.09008 x 100 / Weigh of sample X 1 Where – Burette reading. = vol. in 1Mol HCl consumed in the titration |
