Vol. 15—1961 - NorthEastern Weed Science Society

346 •
.Absornt:j.Qn Qn Exchange Resins I To determine if e. charge exists on the inhibitor
~oleoule, water extraot was leached through coltmms of both amberlite cation
exch~nge resin (m-120) and amberlite anion exchange resin fmA-4QO). The ...
filtrate ,;as testEd fo.r retention Qf inhibitory activity with the results
given in Table 11. .
Table 11. Gemination and Root Gro"lth Following Passage of
Extractions through Exchange Resins
Treatment tlGermUlition Radiole length (mm)
Anion Exchange Resin Filtrate
Cation Bxchange Resin Filtrate
Both Resins 10 5
Water Extract
Control (\'-Jater) 90
o
o
o
There 'WaS no loss of inhibitory activity after leaching through the resin.
Absorpt:j.on Qf Activ:ated CharCOal' A test using 25 m1. of wat.er extract and 2 gra."llS
of activated charcoal (Norit A, netural, deco10rbing charcoal) was shaken together
for 20'minutes on a wrist action mechanical shaker, and filtered on a Buckner
funnel. A test of the activity of the filtrate gave the res~ts in Tab1e'12 •
. Table 12. The Effect of Activated Carbon on the !nhibitor
Trea;t.men1( %Germination RAdicle l;enrlh (mm)
Norit - A
Water Extract o
-
Control (Water) 100 2S
o
, .
The assa;y indicated that no absorption of the. inhibitor by the activated carbor. •
.occurred.
Chromatogranhy: Paper 98rtiti6n chrcmabography techniques were used to further
characterize the inhibitor (s}, ~1ethanol extractions of the foxtail were .
concentrated byheatdng and then deco1orizing. The solvent was prepared from
n-butyl alcohol, acetic acid, and "later, 4-1-5 ratio,by volume. Thismixture
was separated in a senaratory funnel and 'only the organic layer used as the
solvent. The descending method of ohromatography \'65 employed.
A pencil line was drawn across a strip of \fhatman! s filter ryaper, three
inches from .the end. The paper was 20 x 7 inches. The concentrated methanol