Evaluation of a Nitrogen-Cooled, Electrically Heated Cold Trap Inlet for High-Speed Gas Chromatography

Abstract

Gas chromatography has the potential to be a much faster method of separation than is usually realized. If column operating conditions are optimized for speed and injection band width is minimized, some simple separations can be completed in a few seconds. A prototype cryofocusing system for producing narrow injection bands with 0.25-mm i.d. columns is described here. The gas-cooled and electrically heated inlet produces injection bands with widths of about 10-20 ms. In the present study the system is evaluated using mixtures of common organics, including alkanes, aromatics, alcohols, ketones, and chlorinated hydrocarbons. Quantitative trapping and reinjection is achieved for all tested compounds. Coefficients of variation are less than 3% for peak area and less than 0.2% for retention time. Base-line separation of simple mixture is achieved with retention times of less than 10 s. By using the cold trap inlet with a low-dead-volume detector and a high-speed electrometer, the efficiency available from commercial capillary columns can be better utilized, and retention times for some routine separations may be reduced to a few seconds.

Developments and Applications of Field Mass Spectrometers

“…Efforts are currently under way to improve the speed of the chromatograph without sacrificing resolution [16][17][18][19][20], and new, high-temperature columns extend the lifetime of the column and expand the "range and variety of compounds currently studied by GC/MS" [21), In addition, the packed column has largely been replaced by capillary columns. These and other developments in GC are expected to be rapidly incorporated into the instrumentation and practice of field GC/MS.…”

Performance specifications for technology development: Application for characterization of volatile organic compounds in the environment

“…Related technologies such as portable GC/ionmobility spectrometry (Snyder et al 1993) are outside the scope of this report. Efforts are currently underway to improve the speed of the chromatograph without sacrificing resolution (Hyver and Phillips 1987;Mouradian et al 1990;Levine et al 1991), and new high-temperature columns extend the lifetime of the column and expand the range and variety of compounds currently studied by GC/MS (Bowen and Pullen 1989). In addition, the previously ubiquitous packed column has largely been replaced by capillary columns.…”

Development of cryogenic chromatography using thermoelectric modules for the separation of methyltin compounds

“…Cryogenic separation of gas chromatography cooling oven temperature below 08C has also been applied to the determination of nitric oxide [13], xylenes [14], cyanide [15], chloroform, or methylene chloride [16]. Typically, liquid cryogen such as nitrogen or carbon dioxide is used to facilitate operations [17,18]. However, large amounts of cryogen are consumed, which results in increased expense and inconvenience.…”