Abstract
In the polarographic reduction of β-methylumbelliferone, its concentration and wave heights constitute a linear function. In the range of pH 7-10, polarographic halfwave potential and pH also constitute a similar linear function. These were experimentally found to be representable by the following equation: E1/2=-(1.767+0.032 pH) volt.
Umbelliferone (I), β-methylumbelliferone (II), α, β-dimethylumbelliferone (III), α-ethyl-β-methylumbelliferone (IV), and α-propyl-β-methylumbelliferone (V) all showed a simple wave at pH 10.3 and gave n=1 per molecule of polarographic reduction by dropping mercury electrode, their E1/2 being as follows: (I)-1.602v.; (II)-1.870v.; (III)-1.916v.; (IV)-1.920v.; (V)-|>1.920|v.
