Experimental reagent 1.2% glucose 2. 2% xylose 3. 2% maltose 4. 2% lactose 5. 2% sucrose 6. 1% starch 7. Benedict's reagent 8. Morris reagent 9. Serivanov's reagent 10. Baffer reagent 11. Pyrogallol hydrochloric acid solution 12. 10% sodium hydroxide, etc. 2. Constant temperature water bath Take 5 test tubes, add 1mL each of 2% glucose, fructose, xylose, sucrose and 1% starch solution after numbering, and then add 2 drops of Morix reagent. After shaking, tilt each test tube by 45 ° Slowly add 1mL sulfuric acid to the tube wall (do not shake the test tube), let it sit for a while, and observe the color change at the interface between the upper and lower liquid layers. Slightly oscillate the test tube to observe the sulfuric acid layer phenomenon. 2. The Se1iwanoff test Take 4 test tubes, add 10 drops of Selevanov's reagent each after numbering, and then take 2 drops of 2% glucose, fructose, maltose, and sucrose solution respectively, add to the above test tubes, shake well, and put four test tubes into boiling water at the same time Heat in the bath, observe the color change in each test tube, and compare the color development order. 3. Pyrogallol test Take 4 test tubes, number them, add 1mL of resorcinol hydrochloric acid solution, and then add 5 drops of 2% glucose, fructose, xylose, and sucrose solution, shake well, put the test tube in a boiling water bath and boil for 1-2 minutes. Observe the color change in each test tube and compare the results. 4. Benedict test Take 6 test tubes, number them, add 1mL of Benedict reagent, and then add 5 drops of 2% glucose, fructose, xylose, sucrose, maltose solution and 1% starch solution respectively. Shake the test tubes at the same time in a boiling water bath Heat for 3-5 minutes, observe the color change and the formation of precipitation. 5. Barfoed test Take 1 mL of 2% glucose, fructose, maltose and lactose solutions, respectively, and add them to 4 pre-numbered test tubes, and then add 1 mL of Baffer reagent, heat each test tube at the same time in boiling water for 5 minutes, remove the test tube, observe and compare Phenomenon and draw conclusions. 6. Formation reaction and identification Take 6 test tubes and add 20 drops each of 2% glucose, fructose, xylose, maltose, lactose and sucrose solution after numbering, then add 10 drops of 10% phenylhydrazine hydrochloride solution and 10 drops of 15% sodium acetate solution ( Or 20 drops of phenylhydrazine reagent), mix evenly, plug the mouth of the tube with cotton, and then immerse each test tube in a boiling water bath for heating at the same time (note that it is shaken with the addition), record the time of formation of various sugars, after 30 minutes, if it crystallizes The precipitation is not obvious, you can take out the test tube to cool naturally, and rub the wall of the tube with a glass rod to help crystallization. Finally, use a glass rod to take a little sugar crystals on a glass slide, and observe the crystal shape under a low power (80-100 times) microscope. 7. Hydrolysis and identification of sucrose Take two test tubes, add 1 mL of 2% sucrose solution each, add 2 drops of concentrated hydrochloric acid to test tube A, add 2 drops of distilled water to test tube B, shake well, and put the two test tubes into a boiling water bath for 10-15 minutes at the same time. Take out and cool, the nail tube is neutralized with 10% sodium hydroxide solution until the red litmus test paper shows alkaline reaction. Add 1 mL of Benedict reagent to each of the two test tubes. After shaking, heat in a boiling water bath for 2-3 minutes at the same time. Observe and analyze the phenomenon. 8. The role of starch and iodine Take 1 test tube and add 5 drops of 1% starch solution and 2mL of distilled water, then add 1 drop of 1% iodine solution; put the test tube in a boiling water bath and heat it for 5-10 minutes, take out the test tube and cool it. Observe and analyze the phenomena that occur in each operation. 9. Hydrolysis of starch Add 3mL of 1% starch solution to the test tube, then add 0.5mL of 1: 5 sulfuric acid, heat in a boiling water bath for 5 minutes, and cool to neutrality with 10% sodium hydroxide solution. Take 5 drops and react with 1mL Benedict's reagent, heat in a boiling water bath for 3-5 minutes, and observe the phenomenon. Mixing Bowls,Ceramic Bowl,Dinnerware Bowl,Ceramic Rice Bowl Guangdong Qunfa Ceramics Co., Ltd , https://www.qunfaceramics.com
Experimental equipment 1. Common instruments Experimental procedure 1. Molisch test