Full scan: When mass spectrometric determination is performed by the recording of full scan spectra, the presence of all measured diagnostic ions (the molecular ion, characteristic adducts of the molecular ion, characteristic fragment ions and isotope ions) with a relative intensity of more than 10 % in the reference spectrum of the calibration standard is obligatory.

Mass-spectrometric detection shall be carried out by employing MS-techniques such as recording of full mass spectra (full scans) or selected ion monitoring (SIM), as well as MS-MSn techniques such as Selected Reaction Monitoring (SRM), or other suitable MS or MS-MSn techniques in combination with appropriate ionisation modes.

The second method, differential optical absorption spectrometry (DOAS), is a sophisticated, costly technique which nevertheless enables a number of air pollutants to be continuously and simultaneously monitored. These two measurement techniques will be used by the Joint Research Centre of the Commission of the European Communities at Ispra for the purpose of evaluating their reliability. They will be supplemented by means of stationary and mobile measurements involving the use of a mobile laboratory equipped to measure various atmospheric pollutants.