Hydroxylated polyether

The basic polymer appears to be a hydroxylated polyether to which octadecyl chains have been bonded and so it behaves as a reverse phase exhibiting dispersive interactions with the solutes. An example of the separation of a series of peptides is shown in figure 15. The column was 3.5 cm long, 4.6 mm i.d. The solutes shown were (1) oc-endorphin, (2) bombesin, (3) y-endorphin, (4) angiotensin, (5) somatostatin and (6) calcitonon. The separation was carried out with a 10 min linear program from water containing 0.2% trifluoroacetic acid to 80% acetonitrile. 

For HPLC, polystyrene spheres are available with pore sizes ranging from 5 nm up to hundreds of nanometers. Particles with a 5-p.m diameter yield up to 80 000 plates per meter of column length. Silica (Table 26-4) with controlled pore size provides 10 000-16 000 plates per meter. The silica is coated with a hydrophilic phase that minimizes solute adsorption. A hydroxylated polyether resin with a well-defined pore size can be used over the pH range 2-12, whereas silica phases generally cannot be used above pH 8. Particles with different pore sizes can be mixed to give a wider molecular size separation range. 

Abribat, B., Lebigot, Y. and Gaset, A., A simple and inexpensive method for etherification of hydroxylated polyethers in the absence of solvent, Synth. Commun., 1994, 24, 1773. 

Organic polymers TSK-DEAE 5PW Hydroxylated polyether Diethylamino 1000 c... 

Name TSK Phenyl 5 PW Support material Hydroxylated polyether Functional group Phenyl Pore size (A) 1000 Reference c... 

It is only relatively recently that the technology has been developed to produce particulate materials that meet the requirements of HPIEC of peptides and proteins. Table 11 lists these requirements. Historically the first of these substrates was silica, followed by polystyrene highly cross-linked with divinylbenzene, then hydroxylated polyether, poly methacrylates, cross-linked with glycerol and glycols, alumina and most recently, a polyester—polyamine co-polymer. 

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