Page 13 - CS03_Hudz
P. 13
Direct spectra of the extracts were determined
according to the following procedure: the certain
volume of an extract of bee bread was diluted with
50 % ethanol up to 2.0 ml.
50 % ethanol was used as a blank. In fact, each
blank for differential spectrum was used for
measuring direct spectrum of an extract using 50
% ethanol as blank.
For assay of flavonoids we used absorbances of
the extracts and quercetin dihydrate solutions in
absorption maxima in their obtained differential
spectra, appropriate equations for quercetin
dihydrate (y=30,428•X - 0,0262, R² = 0,9717,
and y = 29,945•X -0,0219, R² = 0,997, where X in
mg/ml) and necessary recalculations for volume of
an extract taken for the assay, recalculation
quercetin dihydrate into quercetin.
