Using Comprehensive Two-Dimensional Gas Chromatography to Study the Atmosphere
The atmosphere is a highly complex, highly reactive chemical system. There are a huge variety of emission sources of chemical compounds, both natural and man-made, which have a broad range of reactivities and can be oxidized in the atmosphere to form an even more complicated matrix of oxidation products with a multitude of atmospheric lifetimes. These gas phase species may nucleate to form new particles, be taken up by existing particles or atmospheric water, and eventually be deposited to the ground. Comprehensive two-dimensional gas chromatography (GC×GC) is an ideal tool with which to unravel the complex chemical composition of the atmosphere due to high peak capacity and sensitivity obtained and production of structured chromatograms that can increase the number of compounds identified. The high separation power can also reduce time-consuming sample preparation steps, such as extraction and derivatization, which requires conventional methods. This paper reviews the use of GC×GC to study organic compounds found in the atmosphere. Air and aerosol samples from both field work and simulation chambers have been investigated, and this paper discusses the range of modulator and detectors used, which depends on the target analytes and sampling location.