Quality assurance (QA) has become an increasingly important topic, as environmental monitoring bodies realize that accuracy of measurements can depend very much on how the measurement is taken. This book will describe methods in light of all of the European, US, and international (ISO) guidelines for QA of water analysis. It is the third book in the Water Quality Measurement Series, it tackles the growing problem of developing an international understanding for measurement and data collection. The author gives a detailed overview of: * The purpose of water analysis * Quality systems and quality control * Sources of error including sample contamination * Method validation * Certified reference materials * Data Reporting * Inter-laboratory studies