70 
the quantity of rotenone, a reproducible method could not "be attained, 
Vhittaker and G-lickman (129) in 1934 described a method for the 
detormination of rotenone which was an adaptation of the method of Gnadinger 
and Corl (39) for the pyrethrins. It involved reduction of an alkaline copper 
solution, a modified Folin's solution, "by standard solutions of dextrose and 
of rotenone and "by the unknown solution of rotenoae. The reagents and pro- 
cedure' were almost identical with those described by G-nadinger and Corl. 
A standard rotenone solution in 95-percent ethyl alcohol was used. Results 
for standard roterojao solutions rang^^d from 9.60 mg. of rotenone equivalent 
in reducing action to 1.25 mg. of dextrose to 21.09 mg. of rotenone equiva- 
lent to 4.19 mg, of dextrose. Prom these results an equation was obtained 
for calculating the amount of rotenone present from the equivalent amount of 
dextrose. In a second series of tests the results agreed well with those 
calculated from this equation. The precision of the method was said to be 
usually about 2 parts per thousand. . Traces of chloroform and carbon 
tetrachloride interfered with the determination. 
This procedure was successfully used for the determination of rotenone 
in alcoholic solutions containing antioxidants. 'tJhen the method was applied 
to the analysis of derris root, the results vere much higher than those 
obtained by the crystallization method. For example, two samples which gave 
about 6 percent of rotenone by crystallization gave 11.5 and IS^-S pcrcant by the 
reduction method, A sample with no rotenone gave 15.5 percent by the present 
method. 
