Obviously I just came back in time from my vacation.
About nano columns -- named so after the flow rate -- here a few
indications:
As a vendor we offer three inner diameters and lengths of 5, 15 and 15 cm:
50 micron with a flow rate range from 50 to 150 nl/min and core flow of
about 100 nl/min
75 micron with a flow rate range from 150 to 250 nl/min and core flow of
about 200 nl/min
100 micron with a flow rate range from 200 to 500 nl/min and core flow of
about 325 nl/min
The above indications are for reverse phase columns packed with 3 or 5 um
particles used in peptide/protein separations.
The most popular format lately has been the 75 um I.D. In a recent poster
at the Montreux Meeting in Hilton Head beginning first week of November
we showed together with Finnigan separations between one and twenty fmole
loaded on column and achieved enough coverage so that the first database
search (against Sequest) resulted in the correct hit.
If somebody is interested in this poster and a few other papers that we
or users of our products have published or presented, please make me an
e-mail and I'd be pleased to mail you this literature.
One issue at this level that has to be considered is sample loading: a
sample of 10 ul at 100 nl/min takes 10 minutes -- with this time
span some of the hydrophillic peptides might trickle down the column
which will result in reduced peak height -- about 20 percent less.
Pre-concentration on a small -- and I mean small -- pre-column or guard
column might be necessary followed by desorption onto the nano column.
Hope that helps:
Jean-Pierre
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Jean-Pierre Salzmann
Project Manager
LC Packings (USA) Inc.
80 Carolina Street
San Francisco, CA 94103
Phone (415) 552-1855
Fax (415) 552-1859
E-mail: jpsalzmann@earthlink.net
www.lcpackings.com
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