Volatile organic compounds chromatographic measurement

In order to evaluate the concentration of volatile organic compounds (VOCs), there exist small, portable instruments that contain, essentially, a flame ionisation detector that allows the measurement of the carbon content of the atmosphere without chromatographic separation. 

Chromatographic Measurement of Volatile Organic Compounds (VOCs)... 

Yamamoto N, Okayasu H, Murayama S, Mori S, Hunahashi K, Suzuki K. Measurement of volatile organic compounds in the urban atmosphere of Yokohama, Japan, by an automated gas chromatographic system. Atmos Environ. 2000 34 4441-6. 

Multi-component hydrocarbon standards to provide accurate calibration of instruments (generally gas chromatographs) used to monitor the concentrations of a wide range of volatile organic hydrocarbon compounds (VOCs) in ambient air. These standards currently contain 30 different hydrocarbon species that are important to photochemical ozone formation, with concentrations ranging down to a few parts per billion by molar value. They are disseminated widely in the United Kingdom and the rest of Europe as calibration standards, and as test mixtures for assessment of the quality of international ambient hydrocarbon measurements (often under the auspices of the European Commission - EC). 

Small organic (e.g., formic and acetic) acids are effective volatile IPRs. They impact the retention behaviors of pH-sensitive compounds, changing their charge status and providing pairing anions that may easily interact with protonated solutes. Many chromatographic separations benefit in terms of retention, resolution, and peak shape under acidic conditions due to suppression of silanol activity. Furthermore, the acidity of these IPRs facilitates the formation of the protonated molecular ion [M + H] measured by mass spectrometry in the usual positive ion mode. 

Reamer et al have discussed the applicability of a gas chromatograph coupled with a microwave plasma detector (GC-MPD) for the determination of tetraalkyllead species in the atmosphere. The tetra-alkyllead species are collected by a cold trap. The volatile lead species are concentrated within an organic solvent, separated by a gas chromatographic column and determined by an MPD system which measures the emission intensity of the lead 405.78 nm spectral line. Previous workers have used an acidic solution of hydrochloric acid > activated charcoal , Apiezon L on a silanized universal sup-port the chromatographic support OV-1 and silicone rubber on Chromosorb to collect alkyllead compounds from the atmosphere. 

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