Yong Jian Jiang

US Patent:

20040000519, Jan 1, 2004

Filed:

Jun 28, 2002

Appl. No.:

10/184764

Inventors:

Yong Jiang - Florence SC, US
Michael Miller - Spokane WA, US
Marcus Myers - Salt Lake City UT, US
Andreas Kummerow - Terre Haute IN, US
Soheyl Tadjiki - Salt Lake City UT, US
Marcia Hansen - Salt Lake City UT, US
Thorsten Klein - Diessen, DE

Assignee:

Postnova Analytics, Inc.

International Classification:

B01D011/00

US Classification:

210/634000, 210/635000, 210/656000, 210/748000, 436/161000, 436/180000

Abstract:

An improved field-flow fractionation method and apparatus for the separation of sample species contained in a carrier fluid, wherein a stream of the sample species-containing carrier fluid is forced through a flow channel having a depletion wall , an accumulation wall , side walls, a channel inlet , and a channel outlet , by introducing the sample species-containing carrier fluid into the flow channel through the channel inlet and withdrawing the sample species-containing carrier fluid through the channel outlet a field is applied to the carrier fluid in the flow channel to induce a driving force on the sample species acting across the flow channel from the depletion wall towards the accumulation wall and perpendicular to the orientation of the main axis of the flow channel the sample species are subjected to fractionation as they flow through the flow channel and emerge as sample species fractions at the channel outlet wherein at least one additional stream of sample species-depleted carrier fluid is introduced into the flow channel through at least one orifice and the relative flow rates of the different streams are adjusted such that the stream of sample species-containing carrier fluid is positioned adjacent to the accumulation wall and the sample species-depleted carrier fluid is positioned between the depletion wall and the sample species-containing carrier fluid, no mechanical barrier being provided inside the flow channel between the orifice and the channel inlet for separating the stream of sample species-depleted carrier fluid introduced through the orifice and the stream of sample species-containing carrier fluid introduced through the channel inlet