Direct Estimation of Penicillin G in Small Broth Samples

Thorn, J. A.; Johnson, Marvin J.

doi:10.1021/ac60019a005

Cited by 9 publications

(4 citation statements)

References 7 publications

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“…A delay of half an hour would cause an increase in the pH reading of 0.2 to 0.3 units because ofthe escape of dissolved CO2. Penicillin G determinations were made by the method of Thorn and Johnson (1948). Free phenylacetic acid was determined by the method of Higuchi and Peterson, based on two-phase chromatography, the details of which will be published elsewhere.…”

Section: Experimental Methodsmentioning

confidence: 99%

Evaluation of Precursors for Penicillin G

Singh

Johnson

1948

J Bacteriol

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Section: Experimental Methodsmentioning

confidence: 99%

Evaluation of Precursors for Penicillin G

Singh

Johnson

1948

J Bacteriol

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“…Various techniques have been developed for this purpose. Applications have been made of ultraviolet and infrared spectroscopy (1,10,11), adsorption chromatograms (22), parition procedures involving paper strip (8, 9, 28), as well as packed column chromatography (7,18) and countercurrent distribution systems (4,15). Other methods, such as the chemical precipitation of penicillin G as the V-ethylpiperidine derivative {14, 20) and microbiological differential assays, have been useful {12, 19).…”

Section: Discussionmentioning

confidence: 99%

Penicillin in Broths and Finished Products

Higuchi¹,

Peterson²

1949

Anal. Chem.

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ence between the corrected lines. Thus, by the ferricyanide method, it is permissible to determine procaine penicillin as penicillin and divide the results by 2 if an aliquot containing approsimately 1 mg. of procaine penicillin is used.Results of the analysis of procaine penicillin by this method are compared in Table I1 nith results by the bioassay and iodometric methods. The mean difference between the bioassay and ferricyanide methods is 37 units, and between the bioassay arid iodometric methods it is 239 units. It is obvious that the ferricyanide method can be used for the analysis of procaine penicillins only while they retain their full potency. If a loss in potency is suspected, the compound should be analyzed before and after the addition of penicillinase. The penicillinase prepared in this laboratory ( 2 ) does not interfere with the determination nor affect procaine. Although penicillinase destroys completely the biological activity of penicillin, it does not destroy all its chemical activity as measured by the ferricyanide method. The loss in activity varies with the conditions under which the penicillinase acts but is relatively constant under given conditions. Once this loss has been determined for the given conditions, the difference in the ferricyanide assay before and after the action of penicillinase will give a good estimate of the potency. CONCLUSIOhSThe ferricyanide method possesses several advantages. I t is rapid; determinations require less than 30 minutes. I t is sensitive, using less than 1 mg. of penicillin per determination. I t is simple and needs only a minimum of standard equipment. The number of standard reagents necessary is reduced to one which is stable.The chief disadvantage of the method is that it may be applied only to crystalline penicillin. Many penicillin preparations contain substances that interfere with the procedure. 4CKIOWLEDGMENTSGifts of crystalline sodium penicillin G were received from Merck & Company of Montreal, and Ayerst, McKenna and Harrison of Montreal.Bioassays were carried out under the direction of Ruth Thomas. Frances Connell made the iodometric determinations. LITERATURE CITED(1) Alicino,

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“…Columns of partition adsorbents are useful for the resolution of mixtures of compounds which are decomposed by adsorption on surface-active substances, a noteworthy example being the separation of the penicillins (13,26,56,127). But even under favorable conditions, amino acids were found to be bound by the silicic acid itself as well as by the water in the gel (36,84,85).…”

Section: Methodsmentioning

confidence: 99%

Chromatographic Separations

Strain¹

1949

Anal. Chem.

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Direct Estimation of Penicillin G in Small Broth Samples

Cited by 9 publications

References 7 publications

Evaluation of Precursors for Penicillin G

Evaluation of Precursors for Penicillin G

Penicillin in Broths and Finished Products

Chromatographic Separations

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