QUANTIFYING UNCERTAINTY IN SAMPLING AND ANALYTICAL MEASUREMENT

Many of the provisions of ISO Guide 25 and EN 45001 have been implemen ted in Europe's analytical laboratories particularly in those that hav e been granted accreditation. One element missing so far on the way to well characterized analytical results is measurement uncertainty. Thi s contribution reviews progress made in analytical chemistry particula rly lead by the EURACHEM working group charged with the task of advanc ing approaches and procedures regarding the technical feasibility and proliferation of the related know-how to the practicing laboratories. A worked example is given for the determination of the degree of hydra tion of mineral raw products. Regarding the uncertainty in sampling se veral contributions are enumerated whose importance have to be judged by the analyst on a one by one case.