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Electron capture detector

a sensitive way to spot pollutants London,

A small cylindrical object with a fine metal tube fed through its centre.
Electron capture detector for a gas chromatograph, 1960. Science Museum/ Science & Society Picture Library

Independent scientist James Lovelock (born 1919) developed a highly sensitive electron capture detector in 1956 to detect a range of substances: poisons, carcinogens and pollutants such as nitrous oxide and halocarbons. In the summer of 1967 he used it to measure the supposedly clean air blowing off the Atlantic onto the southwest coast of Ireland and found that it contained chlorofluorocarbons (CFCs). 

Following subsequent experiments Lovelock and his collaborators showed that nearly all of the CFCs ever produced remained in the Earth’s atmosphere. CFCs were a common chemical used in refrigeration and other industrial processes. 

In 1985, British Antarctic Survey scientists announced the discovery of a large hole in the ozone layer, providing startling confirmation of theories that CFCs could deplete ozone. In the 1990s this prompted a worldwide ban of the chemicals. Today these detectors are used in an analytical method called gas chromatography to detect trace amounts of chemicals in a sample.

Science Museum

Chemistry, Physics,
Mill Hill Institute, London
Key Individuals
James Lovelock,