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extraction method to obtain s&tiafactorj.' extraction. Cube roots in general 
were more readily extracted of their rotenone content than were derris roots, 
Preliminary drying was unnecessary, since tne r.oisture content of rerris 
and cube roots as received in the United States was found not to be suf- 
ficiently great to interfere wlfi their analysis. In addition the results 
for rotenone and the purity of the solvate were lower when the r^ot was 
dried either at 100° C. or at 50^ under vacuum before analysis. In the 
chloroform-room temperature-aliquot method replicate results on a sample 
by a single investigator in general agreed within about 5 percent. The 
average difference between the results by the two authors was only about 
3.5 percent. 
As a result of this work Jones and G-raham (72) in 1938 proposed a 
complete extraction and crystallization method for rotenone based on the 
room temperature-aliquot extraction using chloroform and the crystallisa- 
tion as proposed by Jones. The method with some modification has recently 
been adopted by the Association of Official Agricultural Chemista (49) and 
is described in detail later in this section. For roots of abnormally 
high ratio of rotenone to total extract, or in any case of doubt as to the 
completeness of extraction, the alternative room-temperature extraction 
with successive lots of chloroform was suggested. 
Cahn, Phipers, ana Boam (l7) in 1938 r'iscussed methods for deter- 
mining the various constituents of derris extract. They did not agree 
with Jones (65) that the nonrotenone resins exert no solvent effect on the 
rotenone. They cited as experimental evidence one derris extract which 
gave 39 percent of rotenone by the usual method including correction for 
purity, but gave 42 percent of pure rotenone when a first crop was crystal- 
lized and the mother liquor was allov;ed to be adsorbed on charcoal and 
rotenone recovered from the numerous fractions obtained. Hence the authors 
believed that the rotenone content calculated from the crude solvate W8.s, 
by a compensation of errors, closer to the correct valu^:^ than results 
based on pure rotenone. They tested the effect of the removal of the 
alkali-soluble material as suggested by I'artin and Tattersfield (84) , 
and found that in a series of Sumatra-type extracts substazitially the 
same results were obtained by this method as by the nidden rotenone tech- 
nique of Cahn and Beam (ij?) in which excess rotenone is added. Thev also 
discassed results by the Soodhue modification of the Gross and Smith color 
test (40), which determines primarily rotenone plus deguelin (see section 
on Def^elin and Rotenone plus Deguelin). They found that witti the numerous 
samples of derris extract studied (except Sumatra-type extracts) the fol- 
lowing;, relation held: Goodhue value = percent rotenone + 22 ± 3, v/hara the 
values are expressed as percentage of the extract and the rotenone value 
is that for crude rotenone. They stated that this relation had been used 
successfully in the inverse sense to deterinine approximate rotenone con- 
tents from Goodhue values, and was especially valuable for this purpose 
when only small amounts of material were available. 
Rowaan and Van Duuren (108) in 1938 recommended room-temp<»Tature 
extraction with chloroform and removal of an aliquot for the detarmination 
of rotenone in Derri s and Lonchocarpus roots. 
