Abstract
Quantitative separation of free amino acids occurring in green vegetables (nine kinds in total) was carried out by the combined use of ion exchange and paper partition chromatography. Total free amino acids adsorbed on the column of Amberlite-IR-120 were exhaustively eluted with aqueous ammonia (5%), and the eluate was taken to dryness in vacuo. The resulting residue was dissolved in 10ml of distilled water. A quantity of amino acids contained in 0.001ml of this solution was chromatographed on a sheet of paper by the two-dimensional development method, after which 0.1% ninhydrin solution was sprayed on the developed filter paper to confirm the precise position of the spot.
Then each spot was cut off and was steeped into 1% aqueous ninhydrin solution and 10% aqueous pyridine solution, and was boiled on the water-bath for 25min. The colored solution thus obtained was determined by spectroprotometrically at 570mμ. (in the case of proline and hydroxyproline at 440mμ.) The results of experiments were tabulated in Table 2.
