Preparation of Dragendorff's Reagent/ Dragendorff's Reagent (For 200 mL) скачать в хорошем качестве

Preparation of Dragendorff's Reagent/ Dragendorff's Reagent (For 200 mL)

Dragendorff's Reagent mainly used in screening test for Alkaloids. In this video we have clearly explained how to make Dragendorff's Reagent with exact calculation. We have given procedure for making 200 mL of Dragendorff's reagent. Some abbreviation : SMF- Standard Measuring Flask min-minutes Some Alternatives in experimental procedure: 1. We used Magnetic Stirrer for making of solution. If magnetic stirrer not available means you do simple glass rod stirring. 2. For taking of acetic acid (at 1.51 min in video) we used graduated pipette. You can use measuring cylinder or droppers for that. 3. For making of Solution B (4 g KI+ 10 mL water) we used SMF. Instead of SMF you can use measuring cylinder also. 4. The another way for making of Solution B is first weigh 4 g of KI and directly transfer to 10 mL SMF and make the solution to 10 mL with water. Some Important Notes: 1. Bismuth subnitrate is different from Bismuth nitrate, Please ensure that you have Bismuth subnitrate 2. In the process of making solution A , Bismuth subnitrate immediately wont get dissolved. It will take some time to complete dissolve (30-60 min) 3. In the process of making Solution B, first we tried taking 10 mL of water in beaker and to that 4 g of KI was added to dissolve. We got clear solution, but total volume we got 11.2 ml. The exact procedure for making of Dragendorff reagent stock solution is mixing of equal volume of Bismuth subnitrate solution (Solution A) and KI solution (Solution B) (1:1). So better always dissolve KI minimum amount water (in this experiment 8 mL) and use SMF or Measuring cylinder for required volume preparation (in this experiment 10 mL). 3. Always prepare solution A and Solution B freshly