EMEP laboratory intercomparison
General information

EMEP laboratory intercomparison is a central activity in assessing and improving the quality of observation data submitted by Parties to EMEP.

Since 1977, EMEP has arranged laboratory intercomparisons on an almost annual basis, and currently almost 40 rounds have been arranged. The laboratory intercomparisons are conducted through the provision of samples (rain water, filter material) to participating laboratories, who after having analyzed the samples report their results through this website. The test samples are made to represent typical concentration levels at rural and background sites. Results are presented on this website and each participating laboratory receives certificates summarizing the laboratory´s performance. Older results are published in the EMEP-CCC series of reports

Who can participate?

All EMEP laboratories are obligated to participate. As it is fundamental that observations made within EMEP are comparable with data from other regional background monitoring programs elsewhere, the laboratory intercomparisons are open for participation for laboratories directly involved in programs like UNECE ICP Forest, WMO Global Atmosphere Watch, EANET, North American Programs etc. Participation in the intercomparisons is limited to laboratories actively involved in regional scale atmospheric composition monitoring in support of international programs.

What sample types are available?

Sample type B: 6 synthetic samples (two blanks included) for determination of sulphur dioxide and nitric acid on impregnated filters. The filters have been impregnated with 300 µl 1.0 M KOH/10% glycerol in methanol. Different amounts of H2SO4 solution and a nitrate salt solution have been added to the filters.

Sample type C: 4 synthetic samples for determination of nitrogen dioxide. The samples consist of solutions of nitrite are to be diluted according to instruction supplied with the samples.

Sample type G; 4 synthetic precipitation samples. The samples consist of de-ionized water, containing different amounts of sulphate, nitrate, ammonium, strong acid, magnesium, sodium, chloride, calcium and potassium.

Sample type H: 4 synthetic precipitation samples. The samples consist of 0.5% HNO3 and different amounts of Cr, Ni, Cu, Zn, As, Cd and Pb.

Sample type J: 6 synthetic samples (two blanks included) for determination of ammonia on impregnated filters. The filters have been impregnated with 300 µl 3% oxalic acid in methanol and different of an ammonium salt solution have been added to the filters.

Last updated: September 2022 by Anne Hjellbrekke