Page 163 - Tandem Techniques

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This particular type of application of the GC/FTIR tandem system was reported by Diehl et al [4], who
used the system to determine the individual aromatic hydrocarbons in gasoline. By using selected
wavelengths, the maximum sensitivity could be achieved for each aromatic or group of aromatic
hydrocarbons. Diehl et al. used a Hewlett-Packard Model 5890 Series II GC/5965 IRD FTIR, with an
open tubular column 60 m long and 0.53 mm I.D., carrying a 5.0 µm film of stationary phase on the
internal surface. The column was programmed from 40°C to 190 ''C at 2°C per min. and then to 300°C
at 30°C per min. The light pipe and the transfer line were held at 300°C. Employing appropriate
wavelengths, the elution of the aromatic hydrocarbons could be exclusively monitored. The separation
was fairly lengthy, extending well over an hour but the aromatic hydrocarbons could be exclusively
monitored, and the numerous aliphatic and unsaturated hydrocarbons, also present in the mixture, gave
little or no response at the selected wavelength.

Figure 4.13. A
Chromatograms Showing the selective monitoring
of Aromatic Hydrocarbons in Car Exahust
Courtesy of the Perkin Elmer Corporation