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Submitted to: Analytica Chimica Acta
Publication Type: Review Article Publication Acceptance Date: 10/6/2015 Publication Date: 10/22/2015 Citation: Sapozhnikova, Y.V., Lehotay, S.J. 2015. Review of recent developments and applications in low-pressure (vacuum outlet) gas chromatography. Analytica Chimica Acta. 899:13-22. doi: 10.1016/j.aca.2015.10.003. Interpretive Summary: Technical Abstract: The concept of low pressure (LP) vacuum outlet gas chromatography (GC) was introduced more than 50 years ago, but it was not until the 2000s that its theoretical applicability to fast analysis of GC-amenable chemicals was realized. In practice, LPGC is implemented by placing the outlet of a short, wide (typically 10-15 m, 0.53 mm inner diameter) analytical column under vacuum conditions, which speeds the separation by reducing viscosity of the carrier gas, thereby leading to a higher flow rate to gain the most separation efficiency. To keep the inlet at normal operating pressures, the analytical column is commonly coupled to a short, narrow uncoated restriction capillary that also acts as a guard column. The faster separations in LPGC usually result in reduced separation efficiency relative to conventional GC, but selective detection usually overcomes this drawback. Mass spectrometry (MS) provides highly selective and sensitive universal detection, and nearly all GC-MS instruments provide vacuum outlet conditions for implementation of LPGC-MS(/MS) without need for adaptations. In addition to higher sample throughput, LPGC provides other benefits, including lower detection limits, less chance of analyte degradation, increased sample loadability, and more ruggedness without overly narrow peaks that would necessitate very fast data acquisition rates. This critical review summarizes recent developments in the application of LPGC with MS and other detectors in the analysis of pesticides, environmental contaminants, explosives, phytosterols, and other semi-volatile compounds. |
