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Title: Liquid chromatography/Fourier transform IR spectrometry interface flow cell

A zero dead volume (ZDV) microbore high performance liquid chromatography (.mu.HPLC)/Fourier transform infrared (FTIR) interface flow cell includes an IR transparent crystal having a small diameter bore therein through which a sample liquid is passed. The interface flow cell further includes a metal holder in combination with a pair of inner, compressible seals for directly coupling the thus configured spectrometric flow cell to the outlet of a .mu.HPLC column end fitting to minimize the transfer volume of the effluents exiting the .mu.HPLC column which exhibit excellent flow characteristics due to the essentially unencumbered, open-flow design. The IR beam passes transverse to the sample flow through the circular bore within the IR transparent crystal, which is preferably comprised of potassium bromide (KBr) or calcium fluoride (CaF.sub.2), so as to minimize interference patterns and vignetting encountered in conventional parallel-plate IR cells. The long IR beam pathlength and lensing effect of the circular cross-section of the sample volume in combination with the refractive index differences between the solvent and the transparent crystal serve to focus the IR beam in enhancing sample detection sensitivity by an order of magnitude.
Authors:
 [1] ;  [2]
  1. (Fairfield, OH)
  2. (Blacksburg, VA)
Publication Date:
OSTI Identifier:
866031
Report Number(s):
US 4618769
DOE Contract Number:
FG22-81PC40799
Resource Type:
Patent
Research Org:
Virginia Tech Intellectual Properties, Inc. (Blacksburg, VA)
Country of Publication:
United States
Language:
English
Subject:
liquid; chromatography; fourier; transform; spectrometry; interface; flow; cell; zero; dead; volume; zdv; microbore; performance; hplc; infrared; ftir; transparent; crystal; diameter; bore; therein; sample; passed; metal; holder; combination; pair; inner; compressible; seals; directly; coupling; configured; spectrometric; outlet; column; fitting; minimize; transfer; effluents; exiting; exhibit; excellent; characteristics; due; essentially; unencumbered; open-flow; design; beam; passes; transverse; circular; preferably; comprised; potassium; bromide; kbr; calcium; fluoride; caf; interference; patterns; vignetting; encountered; conventional; parallel-plate; cells; pathlength; lensing; effect; cross-section; refractive; index; differences; solvent; serve; focus; enhancing; detection; sensitivity; magnitude; performance liquid; detection sensitivity; liquid chromatograph; preferably comprised; interference pattern; beam passes; dead volume; refractive index; flow cell; fourier transform; liquid chromatography; beam path; calcium fluoride; sample detection; zero dead; circular bore; sample volume; transparent crystal; transform infrared; interference patterns; bore therein; sample flow; spectrometry interface; circular cross-section; flow characteristics; hplc column; interface flow; preferably comprise; directly coupling; /250/356/