Deb's suggestion are good. There are other, probably more tedious ways:
The five times or three times overloading of the valve is something we
often can no longer afford: when one has 500 fmol in 5 ul of sample,
well....
Something that can be done when doing partial loop fills i.e., 5 ul into
a 20 ul loop first pickup in your injection syringe 7.5 ul of mobile
phase A (aqueous), then pick up the 5 ul of sample and the fill the
syringe again with mobile phase A. The sample slug gets sandwiched
between two water slugs and hopefully one will leave behind the second
water slug in the system. Perhaps it would even make sense to use a
bigger loop. Of course it doesn't avoid the decompression problem for the
column... BTW, we have included this technique as a programmed standard
feature in our autosampler.
Good luck: 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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