Interlaboratory calibration of atmospheric nitrous oxide measurements

Samples representative of Northern Hemispheric conditions in mid-1976 were analyzed by 11 laboratories to resolve the question of the absolute tropospheric concentration of nitrous oxide. The laboratories all employed electron capture-gas chromatography for the analysis. After exclusion of one anomalously low determination, the calibration results showed a mean concentration of 323.5 + or - 8.7 ppb v/v nitrous oxide.