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GASOMETRIC DETERMINATION OF CARBOXYL GROUPS IN FREE AMINO ACIDS
Open accessAbstract
The method here presented depends on the fact that a-amino acids, when boiled in water with an excess of ninhydrin (triketohydrindene hydrate) at pH 1 to 5, evolve the CO2 of their carboxyl groups quantitatively in a few minutes. Proline and hydroxyproline yield their carboxyl CO2 in the same manner as the amino acids with primary NH2 in the a position. The reaction is specific for free amino acids in that it requires the presence, in the free, unconjugated state, of both the carboxyl and the neighboring NH, or NH-CH, Group. Several reagents other than ninhydrin react in a similar manner, but of those tried, ninhydrin has given the most precise and specific results. Ruhemann (15), who discovered the reaction of amino acids with ninhydrin, showed qualitatively that monoaminomonocarboxylic acids react with format’ion of ammonia, COZ, and aldehydes.
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Citations
Cited by
Hamilton, P. B., & Van Slyke, D. D. (1943) · Journal of Biological Chemistry · doi:10.1016/s0021-9258(18)51268-0 · Cited by 593
Self-citationHill, R. L. (1965) · Advances in Protein Chemistry · doi:10.1016/s0065-3233(08)60388-5 · Cited by 411
Fry, B., & Carter, J. F. (2019) · PLOS ONE · doi:10.1371/journal.pone.0224297 · Cited by 22
Metadata
- Authors
- Van Slyke, D. D., Dillon, R. T., MacFadyen, D. A., & Hamilton, P.
- Venue
- Journal of Biological Chemistry
- Publisher
- Elsevier BV
- Published
- 1941-11
- Volume
- 141
- Issue
- 2
- Pages
- 627-669
- ISSN
- 0021-9258 (ISSN-L)
- OpenAlex
- W2524744693
- Cited by
- 457
- References
- 0
- FWCI
- 23.10
- Type
- journal article
- Language
- en
- Open access
- hybrid
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- CoChat. (2026). Citation check: GASOMETRIC DETERMINATION OF CARBOXYL GROUPS IN FREE AMINO ACIDS. https://app.cochat.ai/papers/10.1016/s0021-9258(18)72810-x
- The paper
- Van Slyke, D. D., Dillon, R. T., MacFadyen, D. A., & Hamilton, P. (1941). GASOMETRIC DETERMINATION OF CARBOXYL GROUPS IN FREE AMINO ACIDS. Journal of Biological Chemistry. https://doi.org/10.1016/s0021-9258(18)72810-x
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