Journal article
Reconstruction of gas chromatograms from digitally filtered Fourier-transform infrared interferograms
Analytical chemistry (Washington), Vol.61(10), pp.1073-1079
05/01/1989
DOI: 10.1021/ac00185a006
Abstract
Two methods have commonly been used to reconstruct gas chromatograms from interferograms collected during gas chromatography/Fourier transform Infrared spectroscopy (GC/FTIR) experiments. Gram-Schmidt orthogonalization has been applied to a section of the raw Interferograms, or the fast Fourier transform has been applied to the interferogram followed by absorbance calculations over specific frequency windows. The former method is preferred for its ability to operate in real time, while the latter method Is able to produce reconstructions selective for user-defined frequencies. In the work presented here, the trade-offs between these methods are resolved through the use of digital filtering techniques. Band-pass digital filters are mathematical transforms that can operate on Interferogram segments in a frequency-dependent manner. Effectively, a digital filter removes frequency Information outside the range(s) of Interest from the interferogram segment. The sum of squares of the filtered interferogram segment can then be plotted vs interferogram number to obtain the reconstructed chromatogram. Through this procedure, the selectivity of the fast Fourier transform method is obtained at a computational speed comparable to the Gram-Schmidt method. Gas chromatograms from a series of GC/FTIR data sets are reconstructed by use of established techniques and compared to reconstructions produced with the digital filter technique. On the basis of the combination of selectivity, signal-to-noise ratio, and computational speed, the digital filtering approach is shown to be the preferred reconstruction technique.
Details
- Title: Subtitle
- Reconstruction of gas chromatograms from digitally filtered Fourier-transform infrared interferograms
- Creators
- Joanne M BjergaGary W Small
- Resource Type
- Journal article
- Publication Details
- Analytical chemistry (Washington), Vol.61(10), pp.1073-1079
- Publisher
- American Chemical Society
- DOI
- 10.1021/ac00185a006
- ISSN
- 0003-2700
- eISSN
- 1520-6882
- Language
- English
- Date published
- 05/01/1989
- Academic Unit
- Chemistry
- Record Identifier
- 9984217453102771
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