Brief Biography of Prof Mike Ramsey

Mike Ramsey is Emeritus Professor at University of Sussex. After a PhD in Analytical Geochemistry, he conducted research and taught at Imperial College, London for 20 years. He’s published over 160 scientific papers, including many on uncertainty of measurement arising from field sampling, and its effects on decision making.  Mike is Chair of the Eurachem/Eurolab/CITAC/Nordtest/AMC Working Group on Uncertainty from Sampling, which has published International Guidance on this subject. Broader research included NERC-funded project on Multiple Links Towards Integrating Teams for Understanding of Disease and Environment (2007-2008). Chair of European Section of SEGH 2005-2008

Keynote title:

Estimation of measurement uncertainty from sampling at different spatial scales: microns to kilometers

Abstract

Measurement uncertainty (MU) has become the key metric with which to express the quality, reliability and suitability of geochemical measurements. Increasing evidence shows that the dominant contribution to MU is often from primary sampling (UfS), rather than from chemical analysis. The method of UfS estimation usually employed is the ‘duplicate method’, in which duplicate primary samples are taken at locations that are separated by a distance (in space or time) which reflect the ambiguity in the sampling procedure. The heterogeneity of the analyte concentration at the spatial (or temporal) scale of the geochemical survey causes differences in the measurement values for the two duplicate samples, and is thereby included in MU.
International guidance on how to estimate MU that includes UfS from Eurachem¹, and applied by IUGS², focuses on sampling at the macro-scale (m to Km). Case studies will be discussed where, the duplicate method has been shown to be equally applicable for geochemical investigations at the micron scale, for example within single mineral grains. Other studies of analyte heterogeneity over a range of scales (from mm to m)³, support the idea that these empirical methods of MU/UfS estimation are effective at any spatial (or temporal) scale, if the spatial (or temporal) separation of the distance between the duplicate samples is selected in an appropriate way.

  

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¹ Ramsey M.H., Ellison S. L. R., and Rostron P.(eds.) (2019) Eurachem/EUROLAB/ CITAC/Nordtest/ AMC Guide: Measurement uncertainty arising from sampling: a guide to methods and approach, Second Edition,  Eurachem, ISBN 978-0-948926-35-8    http://www.eurachem.org/index.php/publications/guides/musamp
² Demetriades A, Johnson C.C., Argyraki A.(2022), Quality Control Procedures, Chapter 7 of  Demetriades, A., et al., (Editors), 2022. International Union of Geological Sciences Manual of Standard Methods for Establishing the Global Geochemical Reference Network. IUGS Commission on Global Geochemical Baselines, Athens, Hellenic Republic, Special Publication, 2, 515 pp.
³ Ramsey M.H., Grace Solomon-Wisdom G.O. and Argyraki A. (2013) Evaluation of in situ heterogeneity of elements in solids: implications for analytical geochemistry. Geostandards and Geoanalytical Research, 37, 4, 379-391. DOI: 10.1111/j.1751-908X.2013.00236.x