Indexed on: 01 Apr '72Published on: 01 Apr '72Published in: Chromatographia
It is shown that a large number of dansylamino acids can be separated on finely textured paper (Whatman No. 20) if partition chromatography and salting-out chromatography are combined. Partition chromatography (1st dimension) takes place in strongly ammoniacal atmosphere, using a solvent  such as it is usually employed for the separation of dinitrophenylamino acids [11, 22]. The separation of dansylamino acids by salting-out chromatography (2nd dimension) requires the use of relatively strong concentrated aqueous salt solutions. Among the salts that were investigated sodium acetate appears to be the most efficient. When surface-active agents are added to the mobile phases used for the development of the chromatogram (normal primary octyl alcohol in the 1st dimension and sodium dodecylsulphate in the 2nd dimension), better results can be obtained: the reproducibility of the separations is better (1st dimension) and the spots are smaller (2nd dimension). The optimum quantity of each dansylamino acid to be used is 6 nanomoles.
Indexed on: 01 Dec '72
Published on: 01 Dec '72 in Chromatographia