ION EXCHANGE Update 5 Jul 2010

Approximate selectivity scales
cation exchange resins


The sulphonic resin here is a "nominal 8% DVB" product. Resins with higher cross-linking will have higher selectivity values, but the order remains unchanged.
CAUTION: the data are approximate, but the relative order should be right.
Monovalent Sulphonic
(SAC)		 Carboxylic
(WAC)
AmberliteTM example IR120 IRC86
Ion
Li+ 0.85 1.0
H+ 1.00    
Na+ 1.69 0.6  
NH4+ 2.20    
K+ 2.46 0.5  
Rb+ 2.54    
Cs+ 2.80 0.3
Cu+ 5.25    
Ag+ 7.54    
Tl+ 9.75    
Divalent Sulphonic Carboxylic Iminodiacetic
AmberliteTM example IR120 IRC86 IRC748
Ion
UO2++ 0.44    
Mg++ 0.63 0.3 0.8*
Zn++ 0.67 1.5 22
Co++ 0.71 1.9 17
Cu++ 0.73 2.0 550
Cd++ 0.75 1.0 28
Ni++ 0.75 1.4 55
Be++ 0.77    
Mn++ 0.79 1.4 5.0
Ca++ 1.00 1.00 1.00
Sr++ 1.25 < 1 0.6*
Pb++ 1.9 > 1 160
Ba++ 2.2 < 1 0.5*
Ra++ 2.5    
* Doubtful, but the order is Ca > Sr > Ba

See also anion selectivity values.

© François de Dardel