Temperature-tunable selectivity in comprehensive two-dimensional gas chromatography.

A temperature-tunable two-dimensional gas chromatography setup, consisting of three capillary columns with different selectivity, is described. In this setup the selectivity of the primary dimension can be tuned by adjusting the temperature offset of two in series-coupled capillary columns, both columns being part of the primary dimension and positioned in two separate GC ovens. The overall GC×GC separation can be optimized by altering the selectivity of the primary dimension. Besides tuning selectivity, in order to achieve optimal separation, this 2D-GC setup also offers enhanced opportunities for qualitative analysis. Sequentially altering the selectivity of the primary dimension enables one to identify groups of compounds which show similar chromatographic retention behavior.