Anion-exchange ability of neutral hydrophobic hypercrosslinked polystyrene

The characterization of novel neutral hydrophobic hyper-crosslinked polystyrene MN-200 was performed. This resin was shown to exhibit anion-exchange properties in the pH range from 2.6 to 4.3 that can be attributed to the presence of protonated carbonyl groups in the framework of the polymer as no other heteroatoms are present, except for oxygen, responsible for the occurrence of positive charge at the surface. The role of high hydrophobicity of MN-200 in retention of anions is discussed. The anion-exchange selectivity of this sorbent to inorganic anions with diluted perchloric acid solutions as eluent was found to be different from that observed for the common anion-exchangers. The main features of MN-200 are weak retention of sulfate and comparatively strong retention of nitrite that can be useful in practical ion chromatography (IC).