Superficially porous particles with 1000Å pores for large biomolecule high performance liquid chromatography and polymer size exclusion chromatography.

To facilitate mass transport and column efficiency, solutes must have free access to particle pores to facilitate interactions with the stationary phase. To ensure this feature, particles should be used for HPLC separations which have pores sufficiently large to accommodate the solute without restricted diffusion. This paper describes the design and properties of superficially porous (also called Fused-Core®, core shell or porous shell) particles with very large (1000Å) pores specifically developed for separating very large biomolecules and polymers. Separations of DNA fragments, monoclonal antibodies, large proteins and large polystyrene standards are used to illustrate the utility of these particles for efficient, high-resolution applications.

Are sub-2 µm particles best for separating small molecules? An alternative.

Superficially porous particles (SPP) in the 2.5-2.7 µm range provide almost the same efficiency and resolution of sub-2 µm totally porous particles (TPP), but at one-half to one-third of the operating pressure. The advantage of SPP has led to the introduction of sub-2 µm SPP as a natural extension of this technology. While short columns of both SPP and TPP sub-2 µm particles allow very fast separations, the efficiency advantages of these very small particles often are not realized nor sufficient to overcome some of the practical limitations and disadvantages of such small particles. Advantages and disadvantages of columns packed with sub-2 µm particles are described for comparison with the characteristics of larger particles. The authors conclude that while sub-2 µm particles have utility in research studies, columns of larger particles are often better suited for most applications. A suggested 2.0 µm superficially porous particle diameter retains many of the advantages of sub-2 µm particles, but minimizes some of the disadvantages. The characteristics of these new 2.0 µm SPP are described in studies comparing some present sub-2 µm SPP commercial columns for efficiency, column bed homogeneity and stability.