A review of organic aerosol speciation by comprehensive two-dimensional gas chromatography.

Comprehensive two-dimensional gas chromatography (GC × GC) is a mature analytical technique with a far greater separation capability than conventional one-dimensional methods. Atmospheric organic aerosols are comprised of a diverse range of substances which challenge one-dimensional analysis, and for which the two-dimensional method has proved very suitable. The review outlines the basic principles of the two-dimensional separation, and the instrumentation, including detectors. Time-of-flight mass spectrometry offers many advantages, especially with unknown mixtures, and has included use of low and high energy electron impact ionisation. The available methods of data reduction and analysis are outlined. GC × GC may be used in either targeted or untargeted modes, and studies have covered a very wide range of analytes, including many compound groups. Most common are studies of hydrocarbons, including polycyclic aromatic hydrocarbons (PAH), but other work has included oxygenates, chlorinated and nitrogen compounds, and diverse industrial chemicals and consumer products sampled across a range of environments. • Separation capability of GCxGC is ideally suited to organic aerosol analysis. • Nature of the hardware and data processing software is reviewed. • Recent advances include tandem EI ionisation at different electron energies. • Applications include both targeted and untargeted aerosol analysis. • Diverse compound groups have been studied in depth using ToF-MS detection. [ABSTRACT FROM AUTHOR]