Solvent Trapping during Large Volume Injection with an Early Vapor Exit, Part 2: Chromatographic Results and Conclusions

Solvent trapping reconcentrates volatile components after injection or on-line transfer of large volumes. When an early vapor exit is used, typically after a 5-10 m x 0.53 mm i.d. uncoated precolumn, the solvent trapping process differs from that described previously. The visual experiments and the conclusions drawn therefrom, as described in a previous paper, are supplemented with chromatographic results. They show that even hexane ran be quantitatively analyzed in 250 mu l of a pentane solution. Injection of a volume of 250 mu 1 by vaporizer/precolumn solvent splitting was used in the analysis of gasoline in drinking water. Conditions for the transfer of a 1000 mu l volume can easily be adjusted through detection of the front end of the flooded zone by a thermocouple mounted on the outer wall of the precolumn.