Selivanoffs - mStudyGroup.com

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Selivanoff’s Test
To distinguish between ketose and Aldose sugar
Selivanoff’s test is positive only for ketose
sugars and so is answered by Fructose,
sucrose and other fructose containing
carbohydrates.
Selivanoff’s reagent consists of:
 Resorcinol
 Concentrated Hydrochloric acid
Selivanoff’s reagent is prepared by dissolving
0.05g resorcinol in 50ml of distilled water. Add
33ml of concentrated hydrochloric acid (36%) in
it very slowly. Add distilled water to make the
total volume 100ml. In Selivanoff’s reagent, the
final concentration of hydrochloric acid will be
about 12% as the strength of concentrated
hydrochloric acid is 36%
Volume of acid/Volume of solution*Concentration of
acid =33ml/100ml *36%=12%
The carbohydrates are converted into furfural
derivatives by the concentrated HCL present in
the Selivanoff’s reagent. Only furfural derivatives
of ketohexose (5-hydroxymethyl furfural)
condense with resorcinol to form cherry red
colored complex.
fructose+HCl
Hydroxymethyl furfural +
Levulinic acid
Hydroxymethyl furfural + Resorcinol
Cherry red colored complex
Sucrose will also give Selivanoff’s test positive
because the acidity of reagent is sufficient
enough to hydrolyze sucrose to glucose and
fructose.

When sugars are treated with strong acids, on
heating, they are hydrolyzed into
monosaccharide. These monosaccharide
undergo dehydration(removal of water
molecule) by the acids. Depending on the
type of monosaccharide these dehydrated
monosaccharide are called furfural or furfural
derivatives.
C5H10O5 -3H2O C5H4O2
pentose
C6H12O6
Hexose
-3H2O
Furfural
C6H6O3
Hydroxymethyl furfural


Take 3ml of Selivanoff’s reagent and 1ml of
the given carbohydrate solution in a test tube
and mix them.
Boil for 30 seconds only and then cool the
solution. Note the appearance of colour.
The appearance of a cherry red or pink colour
within 30 seconds indicates the presence of a
ketohexose.


The final concentration of hydrochloric acid in
the Selivanoff’s reagent should not exceed
12%. In the presence of excessive strong acid,
aldohexoses may be converted into
ketohexoses and thus it will give a positive
test.
Prolonged boiling may also convert the
aldohexoses into ketohexoses. Hence boiling
should be restricted to 30 seconds.
Experiment
Observation
Inference
3ml of Selivanoff’s
reagent + 1ml of the
given solution mix
them and Boil for 30
sec. and cool the
solution.
cherry red or pink
colour in case of a
ketohexose.
Ketose sugar is
present

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