The determination of amino-acids colorimetrically by the ninhydrin reaction

A. M. Smith; A. H. Agiza

doi:10.1039/an9517600623

Influence of Cations on the Ninhydrin Reaction for the Determination of Amino-Acids

Nature ◽

10.1038/172543a0 ◽

1953 ◽

Vol 172 (4377) ◽

pp. 543-543 ◽

Cited By ~ 23

Author(s):

HANAN MEYER ◽

EMANUEL RIKLIS

Keyword(s):

Amino Acids ◽

Ninhydrin Reaction

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THE QUANTITATIVE ESTIMATION OF FROST INJURY AND RESISTANCE IN BLACK LOCUST, ALFALFA, AND WHEAT TISSUES BY DETERMINATION OF AMINO ACIDS AND OTHER NINHYDRIN-REACTING SUBSTANCES RELEASED AFTER THAWING

Canadian Journal of Botany ◽

10.1139/b64-059 ◽

1964 ◽

Vol 42 (6) ◽

pp. 637-649 ◽

Cited By ~ 28

Author(s):

D. Siminovitch ◽

H. Therrien ◽

F. Gfeller ◽

B. Rheaume

Keyword(s):

Amino Acids ◽

Black Locust ◽

Quantitative Estimation ◽

Freezing Temperature ◽

Freezing Injury ◽

Tree Bark ◽

Freezing Process ◽

Frost Injury ◽

Ninhydrin Reaction

Amino acids and other soluble α-amino compounds are liberated into a leaching medium from tissues of black locust bark, alfalfa, and wheat that are frozen to temperatures which are injurious to the tissues. The amounts liberated increase with lowering in freezing temperature and are proportional to the loss in vital capacity of the tissue. Insignificant amounts of amino acids are released by leaching of non-frozen tissue while a maximum is reached at freezing temperatures which are completely lethal. The amino acids liberated from frozen and thawed tissues must originate from the destruction of living cells by the freezing process. The determination of the concentration of amino acids in the medium in which the plant tissues are leached after freezing can be used therefore as a quantitative method for the estimation of the injury sustained in the freezing.The use of the ninhydrin reaction for the purpose of this determination is described and its application to the estimation of freezing injury and resistance in a variety of hardy and non-hardy tissues of alfalfa, wheat, and black locust tree bark is shown. The extension of this procedure to the determination of injury produced by toxic and other detrimental agents is indicated.

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A Shortened Method for the Fluorometric Determination of Phenylalanine

Clinical Chemistry ◽

10.1093/clinchem/15.1.15 ◽

1969 ◽

Vol 15 (1) ◽

pp. 15-23 ◽

Cited By ~ 18

Author(s):

John A Ambrose

Keyword(s):

Amino Acids ◽

Incubation Temperature ◽

Fluorometric Method ◽

Fluorometric Determination ◽

Reagent Blank ◽

Ninhydrin Reaction ◽

Fluorescence Reaction ◽

Fluorescence Level ◽

Ruhemann’S Purple

Abstract As a result of a study of the classic ninhydrin reaction with amino acids (which results in the production of Ruhemann’s purple), and the fluorescence reaction occurring between ninhydrin and phenylalanine in the presence of a dipeptide, the initial incubation period in the fluorescence reaction was shortened from 2 hr. to 16 min. This improvement in the fluorometric method for the determination of phenylalanine was accomplished by (1) decreasing the initial incubation pH from 5.8 to 5.0, and (2) increasing the incubation temperature from 60° to 85°. A study of the effect of pH on the fluorescence level in both the acid and alkaline reactions demonstrated the presence of fluorescence pH plateaus. These plateaus indicate that the fluorescence level was relatively unaffected by a change in pH within specified ranges. A study of the specificity led to the discovery that the inclusion of a peptide control was necessary to correct for one type of nonspecific fluorescence. To make this correction, it was necessary to add the reading of the serum blank to that of the reagent blank, and to subtract this total from the sample reading.

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