| The proline content was determined by reacting with ninhydrin in an acid medium. |
| The photochemistry of ninhydrin in benzene and water was studied by laser flash photolysis and electron paramagnetic resonance. |
| Another common method involves ninhydrin, which works like invisible ink: when you douse paper with it, the chemical brings out any sweat that may have been left by fingertips. |
| Standards were visualized by ninhydrin reagent and the chromatogram containing phosphorylated proteins was autoradiographed. |
| Amino acid analyzer or HPLC equipment with ion exchange column, device for ninhydrin, post column derivatization and photometric detector. |
| In general the frequency of calibration runs depends on the stability of the ninhydrin reagent and the analytical system. |
