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Switching valve system for direct biological sample injection for LC analysis

  • US 5,468,643 A
  • Filed: 08/10/1993
  • Issued: 11/21/1995
  • Est. Priority Date: 08/28/1991
  • Status: Expired due to Term
First Claim
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1. A valving arrangement, for regulating flows in a liquid chromatography (LC) analysis system which includes sources and flow means to provide controlled flows of a sample, a reactant, a carrier fluid to carry the reactant, and a clean-up fluid for cleaning flow passages, wherein a selected constituent of the sample is to be reacted to form removable particulate reaction products to enable analysis of other constituents of the sample by LC equipment, comprising:

  • a first multi-port valve in fluid communication with respective sources of a sample, a reactant and a carrier fluid, for providing a first plurality of movable passages which are selectively disposable to receive controlled flows from each of said sources, said first multi-port valve being provided with a sample loop and said first plurality of movable passages being movable to a first position so as to selectively direct at least one of said received flows through the sample loop and a second position so as to selectively direct at least one of said received flows to bypass the sample loop; and

    a second multi-port valve in fluid communication with said first multi-port valve for providing a second plurality of movable passages which are selectively disposable to receive a flow output from said first multi-port valve and to convey the received flow output as a conveyed output, said second multi-port valve being provided with filtering means for filtering particulates of predetermined size from a flow containing particulates, said second plurality of passages being selectively movable to a first position so as to convey said received output through said filtering means and a second position so as to convey the received output to bypass the filtering means, said conveyed output being directed to said LC equipment when said second plurality of passages is in each of said first and second positions, said second multi-port valve also being in fluid communication with a source of clean-up fluid so that when said second plurality of passages is in said second position thereof a back-flow of clean-up fluid is directed through said filtering means to purge collected particulates therefrom while said received output is directed to bypass said filtering means.

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