Design considerations in field‐portable GC‐based hyphenated instrumentation

The use of hyphenated GC-based methods in the development of portable chemical-monitoring instruments can offer considerable advantages to the instrument maker. Foremost among these advantages are specificity, speed, and lower costs. In this article, the authors describe the basis for achieving these advantages using examples of three prototype and breadboard instruments developed in their laboratories and give an extended theoretical discussion of the basis for what has been called “transfer-line GC” or TLGC. This TLGC approach to fixed pressure drop chromatography can be used to illustrate overall theoretical limitations of various approaches to high-speed GC for real-time monitoring applications. The three example instruments are a “roving” automated vapor sampling (AVS) TLGC/MS instrument, a breadboard AVS-TLGC/IMS (ion mobility spectrometry) instrument, and a breadboard AVS-TLGC/GC instrument. Discussion will include the application of TLGC theory to instrument design and will use example analyses that focus on the eventual application of this technology to the near real-time detection of highly toxic chemical vapors. © 2000 John Wiley & Sons, Inc. Field Analyt Chem Technol 4: 219–238, 2000