Improvement in flow properties and pH stability of compressed, continuous polymer beds for high-performance liquid chromatography

Continuous polymer beds can be regarded as rods with channels through which the effluent can pass. The original beds had limited pH stability and did not permit especially high flow-rates. These disadvantages were overcome by synthesizing the beds from piperazine diacrylamide (PDA) and methacrylamide (MA) instead of N,N′-methylenebisacrylamide. For high flow-rates, the amounts of PDA and MA and the ratio between them are critical, as is the concentration of ammonium sulphate. The method of synthesis is simple and cost effective. No organic solvents are used. The beds can be prepared either directly in the chromatographic tube or in a breaker in the form of large clusters of small gel particles and then transfered into the tube. The preparation of the beds is described in detail. For a cation exchanger the resolution of model proteins was roughly independent of the bed height (down to 3.5 mm). The resolution was not affected by the flow-rate or even increased when the flow-rate was increased when using a reversed-phase column.