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Analytical Measurement Terminology
Handbook of Terms used in Quality Assurance of Analytical Measurement

Analytical Measurement Terminology
Handbook of Terms used in Quality Assurance of Analytical Measurement

John Green, BP Amoco Pete Houlgate, LGC Jim Miller, University of Loughborough Ernie Newman, Newman Associates Geoffrey Phillips OBE, Consultant Alan Rowley, Alan RowleyAssociates

Coordinating Author Elizabeth Prichard
LGC, Teddington, U K

R9C
ROYAL SOCIETY OF CHEMISTRY

Jetting standards in analytical science

VALID AYALYTlCAL MEASUREMEhT

A catalogue record for this book is available from the British Library
ISBN 0-85404-443-4 LGC (Teddington) Limited, 2001 Published for the LGC by the Royal Society of Chemistry, Thomas Graham House, Science Park,Milton Road, Cambridge CB4 OWF, UK Registered Charity Number 207890 For further information see the RSC web site at www.rsc.org Typeset by Paston PrePress Ltd, Beccles, Suffolk Printed by Bookcraft Ltd, UK

Preface
Production of this guide was supported under contract with the Department of Trade and Industry as part of the National Measurement System Valid Analytical Measurement (VAM) programme.The Handbook was prepared by staff at LGC in collaboration with members of the VAM Education and Training Working Group whose assistance is gratefully acknowledged. Education and training matters have been regarded as an essential aspect of the VAM Programme since its inception in 1988. Clearly the reliability of any measurement depends not only on the availability of instrumentation andmethodology but also on the knowledge, skills and depth of understanding of the analyst. It has been clear to members of the Working Group for some time that the plethora of terminology used in analytical measurements is the source of much confusion, particularly as many widely used definitions are themselves confusing, even to the experienced analyst. It is our hope that the straightforward descriptionsand examples provided in this Handbook will be of assistance to a wide variety of new and experienced practitioners as well as to teachers and lecturers. Mike Sargent Chairman, VAM Education and Training Working Group LGC October 2000

Acknowledgements
The authors would like to thank the following people who looked at various drafts of this handbook. Their advice, criticism and ideas have madethis book a better product . Members of the VAM Education and Training Working Group, in particular: Dr Chris Amodio Professor Joe Connor D r Hywel Evans Dr Colin Graham Dr Sam Lall-jie D r Colin Osborne Mr Douglas Squirrel1 Professor Ron Thomas Professor Alan Townshend Quality Assurance Agency for Higher Education Medway Sciences University of Plymouth University of Birmingham Unilever RoyalSociety of Chemistry Consultant Consultant University of Hull

Our thanks also to Karen Rutland and Fraser Nicholson, LGC. We are grateful for financial support from the Department of Trade and Industry as part of the National Measurement System Valid Analytical Measurement programme. Figure 1 is redrawn from Pure and Applied Chemistry, 1990,62, 1193-1208 with the permission of the InternationalUnion of Pure and Applied Chemistry.

Introduction
This Handbook aims to explain terminology widely used, and sometimes misused, in analytical chemistry. It provides much more information than the definition of each term but it does not explain how to make measurements. Additionally, it does not attempt to provide comprehensive coverage of all terms concerned with chemistry, instrumentation oranalytical science. The authors have addressed primarily those terms associated with the quality assurance, validation and reliability of analytical measurements. The Handbook attempts to place each term in context and put over concepts in a way which is useful to analysts in the laboratory, to students and their teachers, and to authors of scientific papers or books. This approach is particularly...