- 3S •- 
In 1938 Jonea and • Graham (71,')- f5tu(?i?d,, methods .for .t.he q-aantitative 
extraction cf rotPnone from dsrris and cub© roots. The following:; general 
methods v/ere ccmpcred: 
(1) Soxhlet extraction \ir.:.n?r car-tori tetrachloride. 
(2) ioillng-rultip? e extraction:, in v/hich the sample waa 
refliijced vvith t'-^e co Lrent on the c-te:?in '£,ath and theu filtered 
"by Eviction ax.d the jn^vc vas tr&fitef", tvdce with fresh solvent 
in the S'-^jne \\a'r . Benzene, carbon tetrachloride, chlcroforti, 
ethylene dichloride, trichloroeth'^lsne , ethyl acetate, and 
the berzene-sloohol azeotropic mi-.rture v/ere tested as solvents 
by this method. ■ :,;■ • 
iZ) Boiling-aliquot nethod , • in vhich the , sariple was 
treated vdth a weighed amo'int cf solvent, refiv-xed on the 
strain bath, cooled, riolvent added to-,rer>lace that Irst, the 
extract filtert^sd, en J. an aliquot taken. Only benre^.e was 
tried in this :.ethod; 
(4) Rooni temp-jratiire-ri.ulti^^le e:?tisction method, similar 
to method (2) but carried out at roo;n temperatirj-e. Only 
chloroform was tried'. 
(s) Hoom temperature-f^liouot mrtn'-':, ruDstantia] ly the 
Bome as that prooos'-^d bv Bes^a (-5). . Chlorof orrp , beii^ene, and 
ethyl acetate v/ere tested. 
After r^mova: of the solvent, cr^-?,talli'.'ation of the rotenone was 
carried out by the r.ethod proposed by Jones (6o). The marcs from multiple- 
extraction niethods were tested for rotenone by a qualitative color test. 
Tests were r^ade o.^ a la: p-e nujn^er of finely powdored samples of 
derris, cube, and timco roots az-A on one samplo of Tophrosia virginiana 
root. Marc<3 from toe ben73ne-ooilin.ff-i-u.ltiple extraction method and tne 
chloroform-room temperature-mult i"ole extraction method shov/ed practically 
complete extraction of the rotoi.crie . Eesults for rotenone by these 
methods were in agreement with f'iOse by the chloroform-room temperature- 
aliquot method. The latter method was preforred b-'- the authors because 
of its convenience. Various phases of the chloroform-room temperature- 
aliquot method were t-ien studied. It v/.as found that the time of shaking 
during extraction mig:ht be; reduced, to -2 ho^JLrs without seriously; affecting 
the results, but to ensure ■ complete extraction overnight shaking v/as 
advised. Firmness of th-^ sojnole vas an important factor in obtaining 
complete extraction. Results or. co-arcely ground ramplen wore in some 
cases 1 riercent lov/er than on th3 sajne.roptE regxound to a finer size. 
It v;as stated that, to give satisfactory extraction by the aliquoting 
procedure, coarse samples should be gro'jnd so that at least 95 percent 
passed a 60-mesh sieve. Samples containing a high ratio of rotenone to 
total extract were found to be .'nore difficult to extract than tnose with 
lower percentages of rotenone. Wneoi the ratio of rotenone to total 
extract was about 40 percent or over, particularly in the case of derris 
roots, it was necessary to employ the chloroform-room temperature-multiple 
