Abstract
THE iodimetric estimation of procaine penicillin presents difficulties because of the interaction of procaine with iodine. Sodium penicillin to which an equivalent weight of procaine hydrochloride has been added gives results which may be from 3 to 5 per cent lower than for the untreated penicillin. Although the ferricyanide method of Hiscox1 is said to be free from the above objection, we could not obtain consistent results with it, a spread of ± 4 per cent being obtained in a series of determinations on a sample of sodium penicillin. The removal of the procaine ion by precipitation followed by iodimetric determination of the penicillin seemed the most promising line of attack, and sodium silicomolybdate and sodium silicotungstate were both found suitable for this purpose, although the latter possesses certain advantages over the former and is obtainable commercially. Both substances give with procaine salts heavy precipitates which are granular in the presence of sodium chloride (3 per cent) and can readily be centrifuged to a compact mass permitting decantation of the supernatant liquid. Precipitation is virtually complete, and neither precipitant has any action upon iodine or penicillin.
Similar content being viewed by others
Article PDF
References
Hiscox, D. J., Anal. Chem., 21, 658 (1949).
Wild, A. M., J. Soc. Chem. Indust., 67, 90 (1948).
Report of the Analysts Sub-Committee to the Ministry of Health Conference on the Differential Assay of Penicillin, Part II. Analyst, 74, 550 (1949) (with modifications).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
WILD, A. A Method for the Determination of Procaine Penicillin. Nature 165, 818 (1950). https://doi.org/10.1038/165818a0
Issue Date:
DOI: https://doi.org/10.1038/165818a0
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.