Enhancement of signal-to-noise ratios in capillary gas chromatography by using a longitudinally modulated cryogenic system

Russell M. Kinghorn, Philip J. Marriott

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A Longitudinally Modulated Cryogenic System (LMCS) was evaluated for its use in detection enhancement in capillary gas chromatography. The mechanism for chromatographic re-elution for the LMCS is substantially different to other cryogenic devices. The cooled region of the capillary column in which chromatographic bands may be focused is heated by the surrounding oven temperature either by moving the trap along the column, or by moving the column out of the trap. By continually modulating the LMCS at the detector end of the capillary column, signal-to-noise ratios of routine chromatograms can be readily increased by a factor of ten, thus enhancing chromatographic detection. Base widths of peaks, which are often about 2-3 s or more can be easily reduced to 0.3 s when the LMCS is employed in the detection enhancement mode, thus offering a simple avenue to improved peak height sensitivity in capillary gas chromatography.

Original languageEnglish
Pages (from-to)32-38
Number of pages7
JournalHRC Journal of High Resolution Chromatography
Issue number1
Publication statusPublished - 24 Sep 1998
Externally publishedYes


  • Capillary GC
  • Column bleed
  • LMCS
  • Modulation
  • Signal enhancement

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