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Fingerprinting air - new breakthrough at University of Leicester

June 07, 2004

The University of Leicester has developed a new 'air fingerprinting' technique which can detect, in less than a minute, the 'ingredients' of air including that of an individual's breath or perfume.

This technique revolutionises the speed and accuracy by which air composition can be tested and has potential applications in the environmental, industrial and medical worlds.

Scientists also believe the new development may have applications in the forensic field. For example, decomposing bodies emit a variety of volatile organic compounds (VOCs) which may be a tell-tale sign that a body lies buried beneath a patch of ground.

The breakthrough has been made by scientists in the Department of Chemistry at the University of Leicester. Their technique offers high sensitivity and much greater speed than rival methods of air testing.

The research has been led by Dr Paul Monks, Reader in Chemistry, and Dr Andrew Ellis, Senior Lecturer. The team developed a new method for fingerprinting the characteristic signatures of volatile organic compounds (VOCs) in air.

Dr Monks said: "VOCs are produced naturally in the body and some are expelled in our breath. The presence of absence of specific VOCs may be a rapid indicator of certain illnesses.

"A wide range of VOCs are also emitted from man-made sources and these can have a damaging effect on the environment and on human health.

"Chemical plants, oil refineries, gas platforms, vehicle and aircraft emissions, are all major sources of atmospheric VOCs. VOCs are also emitted by numerous consumer products such as paints, solvents, glues, newspapers, and cosmetics.

"Many of the hundreds of different VOCs emitted by these products are toxic and/or carcinogenic and, although usually present in very small quantities, the constant emission into poorly ventilated buildings means that human safety levels are often exceeded.   

"Increasing concern about the impact of VOCs on human health is feeding a growing demand for devices to detect these compounds."

Drs Monks and Ellis specially modified a mass spectrometer in order to develop the new technique: a combination of a proton-transfer ionisation reaction with time-of-flight mass spectrometry has enabled complex mixtures of VOCs to be analysed in under a minute.

The Leicester team became involved in this process as a method for urban pollution monitoring, as they have a number of science goals that required fast fingerprinting. They are developing a number of science projects to look at, for example, ultra-sensitive detection of short-lived atmospheric species that control photochemical smog formation.

Dr Monks added: "The instrument we have developed has the potential to undertake forensic-like investigation of air. In effect we can capture a 'fingerprint' of the air composition, and this has many potential uses beyond urban air monitoring, including medical diagnosis and the development of electronic noses."

Leicester, University of