The Effect of Relative Humidity on the Reaction of Ninhydrin With Amino Acids on Paper Chromatograms

The effect of different relative humidities at 20 °C. on the colored product of ninhydrin with amino acids on paper chromatograms has been investigated. It has been shown that there is only a very narrow range of humidity (35–40%) within which maximum color development for most amino acids can be expected (aspartic acid behaves anomalously), and that the color intensity falls off rapidly on both sides of this maximum.