23.4. Fast GC With fast GC, the GCanalysis time is substantially reduced from the typical analysis times of 10-60 minutes. In order for the reduction in time to provide usefil results, the chromatographic peak width at half height must also be reduced. Consider the importance of extremely narrow peak widths in achieving baseline separation of several compounds that elute within a few seconds. Korytar et al. 71] defined three categories of fast GCaccording to analysis time and peak width at half height. Dagan and Amirav 172] defined a speed-enhancement factor using the same three categories. The speed- enhancement factor takes into consideration the increase in speed obtained by using a shorter column and a faster camer inear velocity as compared to a conventional GC column with op carrier gas inear velocity. Table 2.5 summarizes the definitions of fast GC from the sources cited above.