文档介绍：Experiment III The identification, Test and Assay of Aspirin 1. Purpose (1) To learn about the procedures and the items of identification and assay of drug analysis. (2) To experiment on the analysis of Aspirin. ASPIRIN 2. Procedure and Method (1) Identification Add10mLH 2OBoilandCool 1dropofFeCl 3Violetcolour Principle: COOHOH4+ 6 FeCl 3 COO -O -23Fe Fe+ 12HCl Violetcolour a: Aspirin COOHOCOCH 3COOHOHSalicylicacid Hydrolysis Add10mLNa 2CO 3Boil2min Cool Adddilutesulfuricacidinexcessawhiteprecipitateodourofaceticacid b: Principle: Aspirin COOHOCOCH 3Na 2CO 3 OH COONaCH 3COONa H 2SO 4 OH COOHawhiteprecipitate CH 3COOH a: Clarity of solution b: Salicylic Acid (2) Test a: Clarity of solution b: Salicylic Acid Add45 0C10mLNa 2CO 3Clear 1mLCH 3CH 2OHColdwater50mL 1mLfreshlyprepareddilute ferricammoniumsulfatesolution 1mLCH 3CH 2OHColdwater 1mLfreshlyprepareddilute pared 50mL (3) Assay 20mLneutralethanoldissolved 3dropofphenolphthaleinTitratewithNaOH (accuratelyweighed) Principle: Aspirin COOHOCOCH 3+ NaOH COONaOCOCH 3+ H 2O The formula for the determination of aspirin: (%) 100% 1000 V F T Content W ? ?? ??(3) Ethanol shows acidity when phenolphthalein IS is used, which consumes sodium hydroxide VS leading to high determination result. Therefore,