Polyanions on polysaccharide gels

Humic acids, a class of naturally occurring organic polyelectrolytes found 1n soil and natural waters, have been the subject of considerable study with Sephadex SEC (34-36). Unfortunately, both electrostatic repulsive effects and hydrophobic adsorption influence the chromatography on Sephadex of these complex polyacids. Since the first effect is diminished and the second increased by added salt, solvents that eliminate non-steric effects have apparently not been identified (36). 

Pharmacia) with small particle size and considerable mechanical strength has been introduced (40,41) these columns typically exhibit 1 x 10 plates m l (41) and operate efficiently at flow rates of 0.5 cm min l. However, little information on the charge properties of this packing is currently available, although late elution of the basic protein lysozyme was noted (40), an observation used elsewhere as a diagnostic for the effects of anionic groups in the packing (27). 

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