Practical approaches to fast gas chromatography-mass spectrometry

Fast gas chromatography-mass spectrometry (GC-MS) has the potential to be a powerful tool in routine analytical laboratories by increasing sample throughput and improving laboratory efficiency. However, this potential has rarely been met in practice because other laboratory operations and sample preparation typically limit sample throughput, not the GC-MS analysis. The intent of this article is to critically review current approaches to fast analysis using GC-MS and to discuss practical considerations in addressing their advantages and disadvantages to meet particular application needs. The practical ways to speed the analytical process in GC and MS individually and in combination are presented, and the trade-offs and compromises in terms of sensitivity and/or selectivity are discussed. Also, the five main current approaches to fast GC-MS are described, which involve the use of: (1) short, microbore capillary GC columns; (2) fast temperature programming; (3) low-pressure GC-MS; (4) supersonic molecular beam for MS at high GC carrier gas flow; and (5) pressure-tunable GC-GC. Aspects of the different fast GC-MS approaches can be combined in some cases, and different mass analyzers may be used depending on the analytical needs. Thus, the capabilities and costs of quadrupole, ion trap, time-of-flight, and magnetic sector instruments are discussed with emphasis placed on speed. Furthermore, applications of fast GC-MS that appear in the literature are compiled and reviewed. At this time, the future usefulness of fast GC-MS depends to some extent upon improvement of existing approaches and commercialization of interesting new techniques, but moreover, a greater emphasis is needed to streamline overall laboratory operations and sample preparation procedures if fast GC-MS is to become implemented in routine applications.