Patent ID: 7247189

Claim:
A fluidic switching device for use with a chromatographic separation column for separation of components of a sample fluid F 1 which comprises: (a) a valve comprising a single inlet adapted for receiving a carrier fluid F 2 and with two outlets, wherein the valve is actuated by an actuator for cycling between each of the outlets during the separation; (b) first and second tubular conduits leading from the valve to each of two separate inlets into a common first union with an outlet for F 1 and F 2 between the separate inlets; (c) third and fourth tubular conduits as a connection between the first and second tubular conduits; and (d) a second union between the third and fourth tubular conduits adapted for flow between arms of the second union and adapted so that the sample fluid F 1 can be introduced and flow into the arms from a leg of the second union, wherein the device is constructed so that fluid flow is greater in the first and second conduits than in the third and fourth conduits such that when the carrier fluid F 2 flow is alternately switched in the valve to the one of the first or second conduits, the sample fluid F 1 introduced in the second union is temporarily accumulated as F 1 and F 2 in an opposite conduit of the first or second conduits from the third conduit or the fourth conduit, which accumulated fluid is subsequently flushed from the opposite of the first or second conduit by the carrier fluid F 2 which flows in the opposite first or second conduit upon switching of the valve from one of the outlets from the valve to the other outlet from the valve so that fluid flow from the common union is alternately carrier fluid F 2 or carrier fluid F 2 plus sample fluid F 1 .