Introducing large sample volumes into a GC lets you detect analytes at ppb or even ppt levels, while avoiding sample concentration. However, excess solvent can cause severe band broadening, peak deformation, and column or detector damage. Agilent
7890A and 6890 GCs configured for large-volume injections eliminate such problems. Most of the solvent is evaporated before the analytes are swept into the column. Sample evaporation can occur in a programmable temperature vaporizing inlet, for complex sample matrices, or in the retention gap of a cool on-column inlet with solvent vapor exit, for relatively clean matrices.