Capillary columns in series for GC analysis of volatile organic pollutants in atmospheric and alveolar air

Analysis of volatile organic compounds in air samples requires high resolution capillary gas chromatography. When the sample contains both polar and non-polar compounds, use of only one type of stationary phase can be unsuitable if it leads to the preferential separation of one kind of component having the same polarity at the expense of the separation of other classes of component. This paper describes the coupling of fused silica capillary columns of different polarity and length in order to achieve the separation of such complex mixtures. The combination is evaluated with a 42 component standard mixture and then applied to various atmospheric air samples and alveolar air of exposed subjects to demonstrate the capabilities of the complete sampling and separation technique.