osazone test
DESCRIPTION
TRANSCRIPT
![Page 1: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/1.jpg)
OSAZONE TEST
![Page 2: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/2.jpg)
Introduction
The technique was developed by Emil Fischer, , a German chemist.
![Page 3: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/3.jpg)
IntroductionPhenylhydrazine is the chemical compound
with the formula C6H5NHNH2.
![Page 4: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/4.jpg)
IntroductionOsazones are formed when the sugars react
with a compound known as phenylhydrazine at boiling
point.General Reaction:
![Page 5: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/5.jpg)
Introduction
These sugars are reducing ones which have either a free aldehyde or a ketone group to react with the phenylhydrazine.
![Page 6: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/6.jpg)
Procedures
1. Pipette 1 ml of the phenylhydrazine mixture to a test tube.
![Page 7: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/7.jpg)
Procedures
2. Add 5 ml of the test solution
![Page 8: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/8.jpg)
Procedures
3. shake vigorously to insure complete solution
![Page 9: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/9.jpg)
Procedures
4. Stopper the mouth of the tube loosely with cotton
![Page 10: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/10.jpg)
Procedures
5. Place the tube immediately in a boiling water bath
![Page 11: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/11.jpg)
Procedures
6. Record the time
![Page 12: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/12.jpg)
Procedures
7. Observe the tube
![Page 13: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/13.jpg)
Procedures
8. If a precipitate is formed, record the time and remove the tube from the bath
![Page 14: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/14.jpg)
Procedures
9. Cool off the tube
![Page 15: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/15.jpg)
Procedures
10. Examine the crystals under low power objective
![Page 16: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/16.jpg)
Results and DiscussionsThe reaction is stepwise;
![Page 17: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/17.jpg)
Osazone formation involves hydrazone formation at C-1 of an aldose (or C-2 of a ketose) and oxidation of C-2 (or C-1) of an alcohol group to a ketone (or an aldehyde). The new carbonyl group is also converted to a hydrazone.
Fructose
Mannose Glucose
![Page 18: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/18.jpg)
Osazone crystals have a characteristic shape under the light microscope and help in the identification of the sugar type.
Disaccharides - like sunflowers
Lactose - like tight balls of needles
Monosaccharides - like needle-shaped or broomstick
![Page 19: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/19.jpg)
Making Osazone CrystalsThe difference in the structure of the
monosaccharides is caused by the diverse groups attached to the first and second carbons of the sugar molecules. Their needle-shaped crystals show that the position of the first and second carbons do not matter in the crystal formation.
![Page 20: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/20.jpg)
Viewed under the microscope: Glucosazone
![Page 21: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/21.jpg)
Viewed under the microscope: Fructosazone
![Page 22: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/22.jpg)
Viewed under the microscope: Galactosazone
![Page 23: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/23.jpg)
Viewed under the microscope: Maltosazone
![Page 24: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/24.jpg)
Viewed under the microscope: Xylosazone
![Page 25: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/25.jpg)
Viewed under the microscope: Sucrose
![Page 26: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/26.jpg)
Time to FormThe time needed to create osazone crystals
varies among the various sugars involved, but helps to identify the sugars being tested. For an osazone crystal to be presented from a hot solution will take as long as follows:
fructose, two minutes; glucose, four to five minutes; xylose, seven minutes; galactose, 15-19 minutes; maltose, osazone soluble in
hot water
Actual Time:Xylose – 20 minsGalactose – 25 minsGlucose – 30 minsSucrose – 47 minsFructose – 57 minsMaltose – 59 mins
![Page 27: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/27.jpg)
ApplicationFor identifying sugars esp. Reducing sugars.Osazones are used as dyes
![Page 28: Osazone test](https://reader033.vdocuments.us/reader033/viewer/2022061210/54909e64b479594f368b46a2/html5/thumbnails/28.jpg)
Referenceshttp://www.ehow.com/info_8392949_different-
osazone-crystals.html#ixzz1Rx9lFGBJhttp://www.pua.edu.eg/Version2/Courses2/
Dentistry%20Courses/Freshmen/Spring/BCM101/Practical/Week%202%20practical%20_Chemistry%20of%20carbohydrates_.pdf
http://www.chemistry.ccsu.edu/glagovich/teaching/316/qualanal/tests/osazone.html