MISC 03 - Carbohydrate Tests Flashcards
Test used to detect the presence of reducing sugars
Benedict’s test
Test used to distinguish monosaccharides from disaccharides
Barfoed’s test
Test used to distinguish aldose sugars from ketose sugars
Seliwanoff’s test
Test used to identify the presence of pentoses and pentosans, and to distinguish pentoses from hexoses
Bial’s test
Test used to detect the presence of galactose and lactose
Mucic acid test
Test used to distinguish reducing sugars from each other by the osazones they form with the phenylhydrazide reagent
Phenylhydrazone test
Positive test result (Benedict’s test)
Brick-red Cu2O precipitate
Positive test result (Barfoed’s test)
Brick-red Cu2O precipitate
Positive test result that indicates presence of ketose (Seliwanoff’s test)
Cherry-red condensation product
Positive test result that indicates presence of aldose (Seliwanoff’s test)
Yellow to pink condensation product
Positive test result (Bial’s test)
Blue-green solution
Positive test result (Mucic acid test)
Colorless crystals
Positive test result (Phenylhydrazone test)
Formation of precipitate
Reagent composed of resorcinol in 6 M HCl
Seliwanoff’s reagent
Reagent composed of 5-methylresorcinol in concentrated HCl with a small amount of FeCl3
Orcinol reagent
Reagent composed of 2 g phenylhydrazide HCl, 3 g CH3COONa, and 10 mL distilled water
Phenylhydrazide reagent
Solution composed of 0.1 M glucose, fructose, xylose, lactose, sucrose, and 1% starch
Carbohydrate solution
__________ drops of carbohydrate solution (Formulation used in Benedict’s test)
5 drops
__________ mL of Benedict’s reagent (Formulation used in Benedict’s test)
1 mL
__________ drops of carbohydrate solution (Formulation used in Barfoed’s test)
5 drops
__________ mL of Barfoed’s solution (Formulation used in Barfoed’s test)
1 mL
__________ drops of carbohydrate solution (Formulation used in Seliwanoff’s test)
5 drops
__________ mL of Seliwanoff’s reagent (Formulation used in Seliwanoff’s test)
1 mL
__________ drops of carbohydrate solution (Formulation used in Bial’s test)
5 drops
__________ mL of Orcinol reagent (Formulation used in Bial’s test)
1 mL
__________ drops of carbohydrate solution (composed of galactose and lactose) (Formulation used in Mucic acid test)
3 drops
__________ drops of concentrated HNO3 (Formulation used in Mucic acid test)
3 drops
__________ drops of carbohydrate solution (Formulation used in Phenylhydrazone test)
2 drops
__________ drops of freshly prepared phenylhydrazide reagent (Formulation used in Phenylhydrazone test)
4 drops
