Backflash in gas chromatography occurs when sample solvent expands through vaporization during injection to a greater volume greater than the injection port. This can lead to sample loss, poor reproducibility, carry-over, and ghost peaks. Because expansion of the sample solvent is ~1000 times the original volume, conventional injection port liners (<i>e.g</i>., 4 mm × 78.5 mm) with a volume of ~1 mL can accommodate ~1 μL of sample. Such injections at concentrations of 1–100 ng/μL are often adequate for detection without introducing column overload. However, the use of lower concentrations and/or smaller injection port liners often require pre-concentration techniques to avoid potential backflash by simply injecting larger volumes. New innovations in gas chromatography and miniaturization have resulted in the reduction in volume of injection port liners. The Perkin Elmer Torion T-9 portable GC/MS, designed primarily for gas samples, operates with an injection port liner of approximately 0.05 mL. The significantly smaller liner incites modification to traditional liquid-sample injection protocol. This work describes preliminary designs and use-procedures for zero-solvent-volume thermal desorption injectors.

Eliminating backflash in gas chromatography through the use of zero-solvent-volume thermal desorption injectors

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.