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.