x = (Reading of sample solution) – (Reading of blank)
y = (Reading of standard) – (Reading of standard blank)
v = Volume of solution used for test on the column.
Determination of Riboflavin
The method used to determine riboflavin is described by
Chopra and Kanwar
[11].
Exactly 2g of sample was weighed
into a conical flask. 50mls of 0.2N HCl was added and
boiled in a water bath for one hour. It was cooled and the
pH was adjusted to 6.0 using NaOH. The pH was further
lowered to 4.5 using 1N HCl. This was filtered into 100mls
measuring flask and made to volume. To remove
interferences, two tubes were marked 1 and 2. 1cm3
of
glacial acetic acid was added to each tube and mixed
thoroughly. Then 0.5cm
3
of 3%KMnO4 solution was added
to the tubes. The tubes were kept for two minutes after
which 0.5cm3
of 3% H2O2 was added and mixed well.
UV… Vis was also used instead of flourimeter It was read
at 525nm
Calculation:
Riboflavin content = x x 1
y-x W
x = (Reading of sample 1) – (Reading of sample blank)