Introduction

The determination of both naturally produced and anthropogenic organic species in the atmosphere is a key area in atmospheric chemistry research. Nearest to the earth's surface, within the boundary layer of the troposphere, the determination of hydrocarbon species is important because of their ability to react rapidly with NO, in the presence of sunlight to form photochemical smog. At the other extreme of the atmosphere in the stratosphere, remote measurements of very long-lived halogenated species are required because of their critical impact on ozone destruction. Species such as methane, present throughout the atmosphere, have importance as greenhouse gases and influence global climate and temperature change.

The wide range of both short- and long-lived species that are of interest in atmospheric science coupled to extremely low concentrations and a requirement often for in situ automated analysis has led to the development of many novel chromatographic techniques and methodologies. While some atmospheric species such as organic acids, peroxides and aldehydes have been determined using high performance liquid chromatography, the majority of species are analysed using capillary gas chromatography. The range of compounds that are of interest has resulted in almost every kind of detector finding a role within atmospheric analysis.

This article only deals with the analysis of species found in the gas phase, although many species present in the atmosphere are bound to particles or are in aerosol form. A vast number of methodologies for analysis of these species exist, although in common with gas phase species, gas chromatography plays a vital role in their analysis.

The range of techniques that are in use is so broad that a complete review of analytical methods is impractical. Many individual methods, however, have common components or key procedural steps and these will be discussed. A general outline of a typical atmospheric determination can be broken down into the following steps: sample acquisition, preparation, separation and detection. The first two stages, acquisition and preparation, often prove to be the most challenging. A number of chromatograms obtained from atmospheric analysis are also presented in Figures 1-4. Figures 1 and 2 were obtained from an urban environment and Figures 3 and 4 came from a single field campaign held on the west coast of Ireland to study clean marine air.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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