69 
Determination of Methoxyl Content 
Tattersfield and Roach (l22) in 1923 st.^tud that tlie genuineness of 
derris eX-t?rcts night b,e Gmfirm-^d "by the datcrmin-'tion of their methoxyl 
ccntont. Dctprainations w^rs Tr.gde on the dried ether .ext recti ves by Perkin' b 
modification (91) of the Zeisol !.r,_ethod. The methcicyl content of different 
samples of e-k'tract ran,'^ -d between 15.5 and 14.7 p<2rcent. ' 
■ ' Dimci^'ortt end 'Bw^'rle (p.-^) in 1933 doterr.iincd the me^hoxyl contont'of 
benzr-^ne- extracts of dc-rris root. 
In 1?Z4: DEncjC\'ortt., Buddp, p.nd Eaijjng?rt<^n. (25) described their method 
for the deterjiinstion of the mcthcjcyl content of derris extract. The benzene 
extrp.ctvas' 'transferred directly to the flask of a Zeisel methoxyl determins-.- 
tion apparatus and evjiT'Orat^d to dryness therein. The ueual Zeisel method was 
used. One gr^^n of £;ilv?r iodiae correspor.ded to 0-6394 ^ram of "active 
substance," calculptod as rotenone. This det: rmin:^ oion was said to have only 
an orienting vrTae^ 
Campboll, Sullivan, and Jr-cs '.18) in iS'Sl.det'^rrmin^d the raethoxyyl 
contents of derris and cube roots by tho method of Yieb'^iclc and Schwappach 
as modified by Clerk' (S?-) •, The detcrminetion.'^s w^^re itade on acetone ertractives, 
which had been tr^afd with benzone to rcs'ove tr^^ces of acetone. In 1935 
these invesoi^ators (69) used the S8"?ie method on benzeno e:rtracts of derris 
and cube and calculat.t^d the results to nat:;rial having the same raethoxyl 
content as rotenone. These values v/ere said to be significant, as all the 
kno'.vn naturally occvrri::^- compounds of the rotenone group had approximately 
the saTie methoxyl ccntonc as rotenone, 
Methoxyl determinations •■-ere made by Tattersfield and Martin (l20) in 
1935 on samples cf three s-oecies of ^^tZli* Values were determined on dried 
ether extracts by the method of Cl^^rir Cp.o) <, The results were closely 
correlotea vith the weig.its of the e:;her extract. 
Martin and Tattersfield (84) in 1936 fcmd the methoxyl content of the 
ether extrects of thrc-e samples of derris root in good a;^Teement with that 
of the benzene extrasis. They also mr;de msthoxyl deter-ni nations on various 
fractions of the extracts. 
G-uillavjne and Eerv^ (55) in 1939 used a modification of the Zeisel 
method in det-^-rmining tha methoxyl content of derris, cube, and other rotenone - 
containing materials. The m.othyl iodide forraed was ran into OclU silver 
nitrate and the excr:ss of silver nitrate vras titrated vdth 0,1 I\f sodiiom 
thiosulfgto. The vpluo obtained w^s calculated to m.aterial of tho sane 
methox;rl content as rotenone. The results, an the 11 samples tested, were 
in good agreem.ent vdth those by the modified Durham blue color test used by 
these investigators, 
Kiscellaneoua Determinations 
Danckvrortt and a^dde {PA) in 1953 stated th^t attempts to measure the 
absorption of iodine or bro-m.ine by the double bond of rotenone as a method 
0^ determination l.:^d to practical difficulties. Again in l':^54 they reported 
(25) that, since the halogen coTiSumption was dependent on factors other than 
