By Mark on Wednesday, July 21, 2004 - 04:57 pm:

I have been reading lately about Poroshell packings. It seems like a very clever concept because it allows one to take advantage of the higher efficiency provided by a thin stationary phase film. But by using a film that is thicker than classical pellicular columns, it allows the column to have reasonably good capacity.

My question is this: all of the literature I have seen on it has been with large molecules. Of course large-molecule separation stand the most to gain due to the low diffusivities of large molecules; but it seems to me this type of packing material would also offer substantial benefits for small molecules.

Has anyone tried this - or seem any papers that have done so?

Thanks Mark

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By Chris Pohl on Sunday, July 25, 2004 - 03:37 pm:

Mark,

The benefit of such packings for small molecules will depend upon the retention mode. Assuming that you are mainly interested in reversed phase, the benefits will be minimal. The diffusivities of small molecules aren't low enough to provide much benefit. The lower capacity will be the chief negative although you should be able to operate faster with less solvent