Ion exchange chromatography

Ion exchange resins have different affinities for different ions in solution and are selective for their adsorption. The degree of exchange adsorption of various ions by resins has a general law, but different resins may be slightly different. The main rules are as follows:

Adsorption of Cations by (1)

High valence ions are usually preferentially adsorbed, while low valence ions are weakly adsorbed. Among the ions with the same valence, the ions with larger diameter are strongly adsorbed. Some cations are adsorbed in the following order:

Fe3+>； Al3+>； Pb2+>； Ca2+>； Mg2+>； k+& gt； na+& gt； H+

(2) Adsorption of anions

The general sequence of strongly basic anion exchange resin adsorbing inorganic acid radical is as follows:

SO42->； NO3->； cl->； HCO 3-& gt； Oh-

The general order of anion adsorption by weakly basic anion exchange resin is as follows:

Oh-> Citrate 3->; SO42->； 2-> tartrate; Oxalate II->; PO43->； NO3->； cl->； Acetate->; Bicarbonate-

(3) Adsorption of colored substances

Strongly basic anionic resin is often used to decolorize sugar solution, which has strong adsorption on melanoid (reaction product of reducing sugar and amino acid) and alkaline decomposition product of reducing sugar, but weak adsorption on caramel pigment. This is thought to be because the first two are usually negatively charged, while caramel has a weak charge.

Generally, resin with high crosslinking degree has strong ion selectivity, while resin with macroporous structure has lower ion selectivity than gel resin. This selectivity is larger in dilute solution and smaller in concentrated solution.

You are not a simple ion, but a complex ion, and you don't know what exchange resin it is. Generally, only B can be judged to have the fastest passing speed.