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Related article: Gravimetric 040 046 0.50 a4i 0.49
Volumetric 0.34 0.39 0.58 0.49 0.62
In these assays the amount of ether used, both for the first and second
extraction, was exactly the same in each assay, no attention being paid to
the Mayer test.
The fluidextracts were also assayed by the Squibb process, using refined
petroleum ether for the first extraction in order to eliminate all alkaloids
except cocaine. The fluidextract of coca yielded by this method 0.317
per cent, gravimetric, 0.310 per cent, volumetric. The miscible fluid-
extract assayed 0.44 per cent, gravimetric, 0.15 per cent, volumetric. The
petroleum ether process is more satisfactory as an assay process, since it
allows of extraction until no test is obtained with Mayer's solution, and
it extracts only cocaine.
As confirming the deterioration of this preparation, three fluidextracts
were made in July, 1908, using different menstrua, and were assayed by
the petroleum ether process. When fresh these assayed 0.474, 0.468,
0.483 per cent, respectively. After a year and a half they assayed by the
same process 0.238, 0.258, 0.333 respectively.
Co/cAicum. These preparations were assayed by a modification of the
GordinPrescott method, which has been accepted by the drug laboratory
of the United States Department of Agriculture as giving more accurate as
well as Online Paxil more uniform results than the U. S. P. method. The results are
lower than the U. S. P. assay, but there is less danger of weighing fatty
matters as alkaloid. Even this method is not altogether satisfactory, and
allowance should be made for impurities, as in any gravimetric process.
Under the conditions I do not feel warranted in concluding that there is
any change in these preparations, since slight changes in the process are
likely to cause changes in the results, and the purity of the alkaloids as
weighed is questionable.
Conium. These preparations were assayed volumetrically in order to
avoid the errors of gravimetric results. All the figures given, except the
standardized assay, are volumetric results. The preparation becomes
harder to extract as it grows older, and the Online Paxil last assays were tedious.
Here again imperfect extraction of the alkaloid may easily account for
reported deterioration of conium preparations. I do not consider that
such conclusion is warranted when the added difficulties of extraction are Online Paxil
56 Digitized by VjOOQ IC
882 MINUTES OF THE SECTION ON SCIENTIFIC PAPERS.
Gelsemium, ^The substitution of volumetric for gravimetric assay Online Paxil may
account for the results being all lower than the standard. But the gravi-
metric resiilts in the series (both being recorded) are also slightly lower in
most cases. The differences are not very great, and the uniformity of
results in the Online Paxil volumetric series seems to indicate stability in these prepa-
Hydrastis. The tincture shows a slight but distinctly crystalline pre-
cipitate, likewise Online Paxil the aqueous iluidextract.' Since hydrastis preparations
are known to deposit hydrastine readily, conditions may have much to do
with their permanency.
The old preparations are no more difficult of assay than the new, and
the final alkaloidal residue has but little color. If any Online Paxil change in these
preparations occurs, which seems improbable, it is more likely to be due
to a deposition of alkaloid than to any change in its character.
Ipecac, When lo Cc. of fluidextract is used for assay, as directed by the
Pharmacopoeia, so much coloring matter is extracted that the titration
becomes very difficult. Online Paxil Furthermore, t)ie older preparations require an
increased number of extractions, and this results in a larger proportion of
the coloring matter in the final residue. Hence more care is necessary in
assaying old than for new preparations.
The results do not show any material change in these.