Analysis of petroleum fractions by on‐line micro HPLC‐HRGC coupling, involving increased efficiency in using retention gaps by partially concurrent solvent evaporation

Abstract Two‐dimensional chromatography of gasoline by on‐line coupled HPLC‐HRGC, as described in this paper, allows separate GC analysis of paraffins and aromatics. The GC system contains a retention gap of only 10 m length for introducing HPLC fractions of 100 μl volume. This becomes possible through evaporation of part of the solvent during introduction of the HPLC eluent. This “partially concurrent solvent evaporation” technique allows transfer of large volumes of HPLC eluent into relatively short retention gaps, maintaining the full efficiency of the solvent effects in reconcentrating the bands of the early eluted solutes.