Alcohol retarder column

In reversed-phase (RP) chromatography, a relatively nonpolar support phase binds the complexes (species) being separated, and these are moved by a polar solvent phase (water, alcohols, acetonitrile, or mixtures). Generally, as predictable for RP columns, more hydrophobic contacts on the exterior of a metal complex favor column binding, which retards migration. Examples for RP separations are given in the next paragraphs. 

These are the styrene-divinyl copolymer type (HIO) and include Porapak, Polypak, and Chromosorb 102. Five different Porapaks are available P, Q, R, S, and T, which differ in degree of cross-linking of styrene with ethylvinyl benzene. These polymers give sharp, symmetrical peaks and low retention volumes for water, alcohols and glycols, while less polar compounds are retarded (B28, Hll). The beads are stable up to about 250°C. As they are generally used without liquid phase, there is no bleed from the column. Figure 2 shows the excellent results obtained... 

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