Physical and chemical properties of L-Proline

 Physical properties
 Appearance: white crystal or crystalline powder or colorless needle-like crystals, with a crystal water. Slightly smelly, slightly sweet taste.
 Melting point :210-220 ° C
 Specific rotation: -84.5 ° to -86.0 °.
  Deliquescence: deliquescence.
  Solubility: The product is soluble in water, dissolved in ethanol, acetone and chloroform and insoluble in ether or n-butanol insoluble.
 Storage: Sealed, in dark.
 Isoelectric point (pI): 5.97

 Chemical properties
 From ethanol / ether to get a colorless needle crystal, from the water to be orthorhombic, with a strong sweet taste, and the hydration reaction of ninhydrin test solution was yellow, but red was glacial acetic acid after acidification with ammonium thiocyanate reaction of insoluble salts.
  Note: where N is the valence of 5.