What's novel in the new Eurachem guide on uncertainty from sampling?

A second edition of the Eurachem guide, Measurement uncertainty arising from sampling (UfS),1 has recently been published (Fig. 1), in collaboration with CITAC, Eurolab, Nordtest and the Royal Society of Chemistry's Analytical Methods Committee. This Technical Brief aims to explain how this new second edition differs significantly from the first edition that was published in 2007. The stated objective of this new edition is to incorporate several recent research developments, and to explain how they can be integrated into the estimation of measurement uncertainty in different situations. Both editions are based on the general concept that primary sampling is the first part of the measurement process, and thus usually an important contributor to the uncertainty of any measurement value. The two main approaches to estimating UfS are based upon either empirical methods or numerical modelling. Six worked examples, showing these two approaches, cover a range of application sectors, including food, animal feed, soil and water.