Development of a two-dimensional liquid chromatography system with trapping and sample enrichment capabilities

A two-dimensional HPLC system was developed where “heart-cutting” chromatography, in conjunction with cold temperature trapping, was used to isolate and concentrate specific sample analytes. Low molecular mass polystyrene oligomers were used as model compounds to illustrate the operation of the instrument and evaluate the performance of the trapping system. A critical factor in the operation of the trapping system was the relative degree of retention between the first column and the trapping column. The results of this study showed that up to 32 consecutive heart-cut fractions from the first separation dimension could be stored in a trapping column with good analyte recovery and without significant loss in resolution upon elution on the second separation dimension.