Multidimensional liquid-gas (LC-GC) chromatography for the rapid determination of sautred hydrocarbon contamination in food

The present research is directed toward the use of a rapid heart-cutting LC-GC method for the analysis of mineral oil saturated hydrocarbons, contained in a series of widely-consumed foods (vegetable oils, margarine, crisps, milk, tinned tuna, baby food, etc.). The automated LC-GC experiments were carried out by using a system equipped with a syringe-type interface, capable of both heart-cutting and comprehensive two-dimensional analysis. The first dimension separation was achieved on a silica column, operated under isocratic conditions (hexane). The heart-cuts were transferred to a programmed temperature vaporizer. After the large volume injection, the target analytes were separated in a rapid manner (~ 9 min) using a micro-bore GC capillary. The overall LC-GC run time enabled the analysis of circa 4 samples/hour. Quantification was performed by using external calibration, in the 1-200 mg/kg range. More than fifty commercial samples were subjected to analysis, with various degrees of contamination found in many samples.