Scheme for the Identification of Unkown Substances
21
SCHEME FOR THE IDENTIFICATION OF UNKOWN SUBSTANCES Physical properties Chemical properties Presented by Dr Nada Soliman
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Transcript of Scheme for the Identification of Unkown Substances
SCHEME FOR THE IDENTIFICATION OF
UNKOWN SUBSTANCESPhysical propertiesChemical properties
Presented byDr Nada Soliman
name…………number……...
Number of the unknown Physical properties:1. Shape2. Color3. Odor4. Taste5. Solubility6. Reaction7. Heat dry test
Chemical properties
test observation result
unknown possibilities:
CHO proteinReducing non reducing heat-coagulable non heat-coag
Glucose starch sucrose albumin and peptone gelatinMaltose globulineLactose(consideredAs onesolution)
3 solutions 3 solutions
Physical Properties
1. ShapeA. Powder e.g. starch.B. Crystals e.g. sugars.
2. Color.3. Odor.4. Taste: The unknown substance
may be:A. Sweet e.g. sugarsB. Tasteless e.g. starch
5. Solubility:A. Cold water: e.g. sugars urea,….etc.B. Hot water: e.g. starch and gelatin
6. Reaction7. Heat dry test: Heat a small portion of
the unknown substance in a dry test tube
A. Odor of burnt bread e.g. starch.B. Odor of caramel e.g. sugars.C. Odor of burnt haire.g. Protein
Chemical Properties
We have 3 solutions of protein, one of them : egg white solution (source of albumine and globuline)is a natural solution which contain beside protein, CHO
So we start the scheme with biuret test (test specific for protein)
Biuret test Heat coagulationtest
Millon’s test
test Observation Result
1. Biuret test2. Heat coagulation
test
3. Salting out
4. Millon’s test
Violet color White ppt in the
upper part of the test tube
ppt with ½ saturated (NH4)2SO4 solution
ppt with fully saturated (NH4)2SO4 solution
Brick red ppt
Protein solution heat coagulable
protein (albumin & globulin)
Globulin
Albumin
Protein contain
Tyrosine
Biuret test Heat coagulationtest
Millon’s test
test Observation result
1. Biuret test2. Heat Coagulation
test
3. Millon’s test
4. Sulfur test
Violet color No white ppt in the
upper part of the test tube
Brick red ppt
Black ppt
Protein solution non-heat
coagulable protein (peptone or gelatin)
Protein containing tyrosine: peptone
Proteine containing sulfur containing aa (cystine et cysteine): peptone
Biuret test Heat coagulation test
Millon’s test
Test Observation Result
1. Biuret test 2. Heat coagulation
test
3. Millon’s test
4. Sulfur test
Violet color No white ppt in the
upper part of the test tube
No brick red ppt
No Black ppt
Protein solution non-heat
coagulable protein (peptone or gelatin)
Protein doesn’t contain tyrosine: gelatin
Protein doesn’t contain cystine or cysteine: gelatin
biuret test
violet color no violet color (protein) (not protein)
heat coagulation test
whit ppt no white ppt (heat- coagulable (non- heat coagulable protein: albumin) protein: peptone or & globulin ) gelatin)
millon’s test millon’ s test
brick red ppt brick red ppt no brick red ppt (tyrosine) (protein contain (doesn’t contain tyrosine: tyrosine: peptone) gelatin) sulfur test sulfur test
black ppt no black ppt (protein contain (doesn’t contain sulfur aa: peptone sulfur aa :gelatin)
Biuret test molisch test Iodine test
test observation result
1. Biuret test2. Molisch test3. Iodine test4. Fehling after
hydrolysis
No violet color Reddish violet ring Deep blue Color Red ppt
Not protein CHO solution starch Products of
hydrolysis of starch have free anomeric carbon atoms
Biuret test Molisch test Iodine test Fehling test
Essai Observation Resultat
1. Biuret test2. Molisch test3. Iodine test4. Fehling test
5. Osazone test
No violet color Reddish violet ring No Deep blue Color Red ppt
Needle- shaped crystals
Plate- shaped crystals
Rosette- shaped crystals
Not protein CHO solution Not starch Reducing sugar
( glucose, maltose ou lactose)
Glucose
Maltose
lactose
Biuret test Molisch test Iodine test Fehling test Seliwanoff test
Essai Observation Result
1. Biuret test2. Molisch test3. Iodine test4. Fehling test
5. Seliwanoff test
6. Fehling after hydrolysis
No violet color Reddish violet ring No Deep blue Color No Red ppt
Red onion peel color
Red ppt
Not protein CHO solution Not starch Non Reducing
sugar (sucrose) Sucrose
Products of hydrolysis of sucrose have free anomeric carbon atoms
molisch test reddish violet ring no reddish violet ring (CHO) (not CHO)
iodine test
Deep blue color no deep blue color (starch) (not starch)
Fehling after Fehling test hydrolysis red ppt no red ppt (reducing sugar) (non-reducing)
osazone test seliwanoff test
crystals red onion peel color ( sucrose) fehling after hydrolysis
