Proficiency Testing in Analytical Chemistry (Valid Analytical Measurement) - Softcover

Walker, Ron; Thompson, Mike; Lawn, Richard

Softcover

ISBN 10: 0854044329 ISBN 13: 9780854044320

Verlag: Royal Society of Chemistry, 1997

Inhaltsangabe

This book deals exclusively and comprehensively with the role of proficiency testing in the quality assurance of analytical data. It covers in detail proficiency testing schemes from the perspectives of scheme organisers, participant laboratories and the ultimate end-users of analytical data. A wide variety of topics are addressed including the organisation, effectiveness, applicability, and the costs and benefits of proficiency testing. Procedures for the evaluation and interpretation of laboratory proficiency, and the relation of proficiency testing to other quality assurance measures are also discussed. Proficiency Testing in Analytical Chemistry is an important addition to the literature on proficiency testing and is essential reading for practising analytical chemists and all organisations and individuals with an interest in the quality of analytical data.

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This book deals exclusively and comprehensively with the role of proficiency testing in the quality assurance of analytical data. It covers in detail proficiency testing schemes from the perspectives of scheme organisers, participant laboratories and the ultimate end-users of analytical data. A wide variety of topics are addressed including the organisation, effectiveness, applicability, and the costs and benefits of proficiency testing. Procedures for the evaluation and interpretation of laboratory proficiency, and the relation of proficiency testing to other quality assurance measures are also discussed. Proficiency Testing in Analytical Chemistry is an important addition to the literature on proficiency testing and is essential reading for practising analytical chemists and all organisations and individuals with an interest in the quality of analytical data.

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Proficiency Testing in Analytical Chemistry

By Richard E. Lawn, Michael Thompson, Ronald F. Walker

The Royal Society of Chemistry

Copyright © 1997 LGC (Teddington)
All rights reserved.

ISBN: 978-0-85404-432-0

Contents

Chapter 1 Proficiency Testing in the Context of Valid Analytical Measurement, 1, 
Chapter 2 The Role of Proficiency Testing in Analytical Quality Assurance, 7, 
Chapter 3 Performance Scoring in Proficiency Testing – An Overview, 15, 
Chapter 4 Organisation of Proficiency Testing Schemes – General and Management Aspects, 24, 
Chapter 5 The Organisation of Proficiency Testing Schemes – Technical Aspects, 47, 
Chapter 6 Participation in Proficiency Testing Schemes by Analytical Laboratories, 73, 
Chapter 7 Proficiency Testing for End-users of Analytical Data, 81, 
Chapter 8 Proficiency Testing – The Future, 88, 
Glossary of Terms and Acronyms, 90, 
Appendix 1: Eurachem-UK Register of Proficiency Testing Schemes, 97, 
Appendix 2: Proficiency Testing Schemes Taking Part in the VAM, 100, 
Appendix 3: Examples of Performance Reports Issued by PT Scheme Organisers, 101, 
References, 107, 
Subject Index, 109, 

CHAPTER 1

Proficiency Testing in the Context of Valid Analytical Measurement

1.1 What is Proficiency Testing?

A proficiency testing (PT) scheme comprises the regular distribution of test materials to participating laboratories for independent testing. The results are returned to the organiser of the scheme who makes an analysis of the results and reports them to all of the participants. The primary function of the scheme is. to assist the participants to detect shortcomings in their execution of the test procedures and apply suitable remedial measures to make up any deficiency. This is a particularly important function in analytical measurement, which is fraught with practical difficulties and prone to unsuspected errors. As well as this primary 'self-help' ethos, there is also an element of accreditation in many proficiency testing schemes. Accreditation agencies will normally expect candidate laboratories to participate satisfactorily in a proficiency test in areas of analytical measurement where one is available.

Proficiency tests in analytical chemistry usually comply with a particular type, where the distributed materials are portions taken from an effectively homogeneous bulk material that resembles the normal test materials as closely as possible. The materials are distributed for analysis with choice of methods open, although participants should use their usual procedures. The estimated true value of the measurand is not revealed to the participants until after the collection of all of the results. The proficiency test therefore provides for the participant an independent check on the accuracy of the analytical result, albeit only at the time of the test. As the scheme is a regular event, it allows a laboratory to compare its results (i) with an external standard of quality, (ii) with the results of its peers and (iii) with its own past performance. Participation in a proficiency testing scheme therefore results in a much higher proportion of the participant laboratories reaching a satisfactory standard than would otherwise be the case. However, no consistent long-term improvements in performance will result unless the participation is in the context of an integrated quality assurance system within each laboratory.

Care must be taken not to confuse proficiency testing with other types of interlaboratory study, that is those designed for validating analytical methods or certifying reference materials. The operational protocols for these three types of study are quite distinct (Section 4.3).

1.2 Importance of Valid Analytical Measurements

Accurate and dependable analytical measurements are essential requirements for sound decision-making on many issues of vital interest to society. Environmental scientists and regulatory authorities need reliable data on the nature and extent of environmental contamination in order to identify cost-effective pollution-abatement technologies. The health and safety of the working population is safe-guarded by a number of regulations that prescribe maximum permissible levels of hazardous substances in the workplace environment. The effective enforcement of these regulations depends critically on the availability of sound analytical data. The welfare of the population at large is dependent on water and food supplies of high quality and this quality can be checked only by the careful application of a variety of different analytical techniques, each of which is often of considerable technical complexity, and therefore prone to error.

When valid measurements are not realised, data of poor quality are reported by a laboratory. In such circumstances the ensuing problems and costs for the end-user of the analytical data can be substantial and are associated with such consequences as:

• the costs involved in repeat measurements to correct poor data;

• the faulty decision-making that ensues when invalid results are acted upon;

• damage to reputation and credibility that results when an end-user is associated with poor data;

• possible loss of business where the end-user's customer is compromised by poor data;

• any legal and financial liability incurred from the use of poor data.

Hence it is important that those who commission laboratories to undertake analytical measurements on their behalf appreciate the critical need to select only competent laboratories.

There are a number of key concepts and practices that laboratories can apply to help them to improve, maintain and demonstrate the validity of their data, namely the use of properly validated methods, the use of internal quality control procedures, the use of certified reference materials, third party accreditation and participation in proficiency testing schemes.

1.3 The VAM Proficiency Testing Project

The material in this book has been enhanced by unique information gathered by the authors during a project on proficiency testing completed in 1994 as part of the UK Government's Department of Trade and Industry's Valid Analytical Measurement (VAM) Initiative. This wide ranging project studied a number of important aspects of proficiency testing (PT). An efficacy study was undertaken to evaluate the effectiveness of proficiency testing as a means of improving the quality of analytical data and the essential features of effective schemes were identified. An investigation was carried out to establish the degree to which good performance in one particular test in a PT scheme correlates with good performance in a second, different, test within the same scheme. Such information contributes to the design of cost-effective schemes, by enabling optimum information on analytical proficiency to be obtained on the basis of a laboratory's performance in a limited number of critically selected tests. Other factors relating to the costs, benefits and resource requirements associated with proficiency testing were also reviewed.

The structure and operation of several UK proficiency testing schemes were surveyed, from the perspectives of scheme organisers, participant laboratories and end-users of analytical data (i.e. customers of analytical laboratories). Organisers of 18 schemes in the fields of chemistry and microbiology took part in the survey, which was conducted by means of face-to-face interviews and questionnaires; the participant...

Details zur Ausgabe

• Verlag: Royal Society of Chemistry
• Erscheinungsdatum: 1997
• Sprache: Englisch
• ISBN 10: 0854044329
• ISBN 13: 9780854044320
• Einband: Taschenbuch
• Anzahl der Seiten: 122
• Kontakt zum Hersteller: Nicht verfügbar
• Verantwortliche Person: Buchpark GmbH; gpsr@buchpark.de; ; Krügerweg 1; Trebbin; Brandenburg; 14959; Deutschland