Programmed large volume injection mode

Some analytes are volatile enough to be analysed by GC, but too involatile to give sufficient sensitivity by headspace injection modes. In these cases, all may not be lost. The programmed temperature vaporiser (PTV) can provide a means of selectively injecting the desired analyte onto the column whilst excluding undesired components such as solvents and involatUes. This is variously known as selective extraction or selective exclusion. It permits large volume injections (LVI) and difficult matrix introduction (DMI). 

Bosboom, J.C. Janssen, H.G. Mol, H.G.J. Cramers, C.A. Large-volume injection in capillary gas chromatography 9. using a programmed-temperature vaporizing injector in the on-column or solvent-vent injection mode. J. Chromatogr. A,... 

The methods for transferring LC fractions to GC were developed hand in hand with large-volume GC injection. They mostly involved on-column techniques, since these show best performance and follow rather simple rules. The main drawback, the sensitivity to nonevaporating by-products, is not important, since efficient preseparation by LC is also efficient in removing the contaminants . The principal alternative, programmed temperature vaporizing (PTV) injection in solvent split mode, has rarely been applied. 

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