Most interfaces between a gas chromatograph (GC) and a Fourier transform infrared (FT-IR) spectrometer for the on-line measurement of the spectra of eluting peaks have been designed for use with 1/8 in. o.d. packed GC columns, and the light-pipes are too large for GC/ FT-IR measurements of peaks eluting from capillary columns without degrading the GC resolution. The volume of a light-pipe for GC/FT-IR should be large enough to ensure that as much of the sample as possible is present in the cell during the measurement of the spectrum, but small enough that the GC resolution is not seriously degraded. It has been shown that the optimum GC/FT-IR sensitivity is obtained when the volume of the light-pipe, Vcell, is equal to the volume of carrier gas containing a GC peak between its half-height points, V1/2. For peaks eluting from lightly loaded 1/8 in. o.d. packed columns, V1/2 is usually about 5 ml or greater, while for peaks eluting from capillary columns V1/2 is considerably smaller than this. If a support-coated open tubular (SCOT) column is used, a typical value for V1/2 is 0.5 ml, and if wall-coated open tubular (WCOT) columns are used, V1/2 may be 50 μl or even lower. Thus, if GC/FT-IR techniques are to be used for the identification of components of mixtures separated by capillary columns, light-pipes of smaller volumes than the 3 ml light-pipes used on commercial GC/FT-IR systems must be used.
Donald Kuehl, Gabor J. Kemeny, and Peter R. Griffiths, "Identification of Peaks in Capillary Column Gas Chromatograms at the Nanogram Level by Dual-Beam Fourier Transform Infrared Spectrometry," Appl. Spectrosc. 34, 222-224 (1980)
References are not available for this paper.
OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.