On-line high-performance liquid chromatography-solvent evaporation-high-performance liquid chromatography-capillary gas chromatography-flame ionisation detection for the analysis of mineral oil polyaromatic hydrocarbons in fatty foods

An automated on-line method is described that involves a first LC separation on a large column, evaporation of a 6-ml fraction in an on-line solvent evaporator, a second LC separation using a different mobile phase, fractionating the components of interest and transfer to GC through the in-line vaporiser/overflow interface. The method is designed for the injection of a large amount of food extract (e.g. up to 200 mg of fat) and is applied to the analysis of mineral oil material in a linseed oil.