Our purpose is to show by means of a quantitative method for determination of hydrindantin derivatives that previous concepts of the mechanism of the reaction of ninhydrin with amino acids are inadequate or erroneous, and to show facts supporting a new concept. The main facts are as follows: (a) Hydrindantin forms when amino acids react with ninhydrin (Ruhemann (1) ; Abderhalden (2)) ; (b) it r...

A simple method was created and implemented through the technology of ink-jet printing to study the effects of three chemical factors (chemical reagents) to the ninhydrin reaction. The effects of each single reagent and their interactions on the reaction were studied in one experiment. The three reagents all have effects on ninhydrin reaction, and the effects under the different combinations of...

Ninhydrin reactions using manual and automated techniques as well as ninhydrin spray reagents are widely used to analyze and characterize amino acids, peptides, and proteins as well as numerous other ninhydrin positive compounds in biomedical, clinical, food, forensic, histochemical, microbiological, and nutritional and plant studies. Ninhydrin in aqueous solution reacts with α-amino acids to g...

Some years ago Grassmann and von Arnim (1, 2) described in detail a red reaction product of proline and ninhydrin formed at pH 7; it was suggested that this reaction product might be of use as a measure of the concentration of proline in biological materials. Hydroxyproline gave a similar though not identical reaction product. More recently, Van Slyke et al. (3), in studies of the ninhydrin met...

In the present study, we propose a simple and sensitive method for the determination of total amino acids without any separation steps. The procedure described here is based on the ninhydrin derivatization reaction with amino acids, followed by surface-enhanced Raman scattering (SERS) measurements of the producing mixtures. A good linear correlation of excess ninhydrin SERS signals and the log ...

Enhancement of footwear impressions, using ninhydrin or ninhydrin analogues is not considered common practice and such techniques are generally used to target amino acids present in fingermarks where the reaction gives rise to colour and possibly fluorescence. Ninhydrin and two of its analogues were used for the enhancement of footwear impressions in blood on various types, colours and porositi...

A new sensitive spectrophotometric method has recently been developed for the trace determination of cyanide with ninhydrin. Cyanide ion was supposed to act as a specific base catalyst. Nevertheless, this paper demonstrates that the reported assay is based on a novel reaction of cyanide with 2,2-dihydroxy-1,3-indanedione, which affords purple or blue colored salts of 2-cyano-1,2,3-trihydroxy-2H...

The mean lethal dose of patulin for the chicken embryo injected in the air cell before incubation was determined to be 68.7 mug and that for the 4-day-old embryo was 2.35 mug. Both patulin (1 to 2 mug/egg) and the reaction mixture between patulin and cysteine (15 to 150 mug of patulin equivalents) were teratogenic to the chicken embryo. At least two ninhydrin-negative and four ninhydrin-positiv...

This paper presents a convenient micromethod for the estimation of amino acids, based on the reaction with ninhydrin. The ammonia formed in this reaction is determined, after elimination of the interference from ninhydrin with superoxol, by addition of saturated potassium hydroxide, aeration, and titration with standard acid. The application of the reaction with ninhydrin is one of the most spe...