Separation and determination of naphthalene-disulfonic acids by ion exchange resins
1963 Volume 12 Issue 12 Pages 1170-1174
Details
1963 Volume 12 Issue 12 Pages 1170-1174
A salting-out chromatography using a weakacid cation exchange resin and an aqueous salt solution as adsorbent and developer has been applied to separations of naphthalene-1, 5- and -1, 6-disulfonic acids and also of naphthalene-2, 6- and 2, 7-disulfonic acids.
In order to obtain the most suitable column size and developer for the separation of these isomers, distribution coefficients (Kd) of the acids between Amberlite CG-50 of 100200 mesh and calcium-, magnesium- and zinc chloride solutions were measured. As the result, Kd was found to be varied by changing the nature of salt and also the concentration and the pH value of its solution. When the acids were eluted with 2M calcium chloride of pH 2.0 or 4.0, through the columns of 11 mmφ×214 mm and 10 mmφx230 mm packed with the same resins of 200400 mesh, the separations of isomers were complete.
The acids in eluants were determined spectrophotometrically with good results.
A stepwise elution analysis changing the con-centration of developer from 2M to 0.5M with the programming temperature column chromatography was tried to accelerate the development of the latter peak, and it was found quite powerful.
