ABSTRACT
Validation and quality assurance (QA) are topics of increasing importance in analytical chemistry. The official definition of a quality system given by the International Organization for Standardization (ISO) is “the management system used to direct and control an organization with regard to quality.” Certified reference materials are cornerstones of modern analytical QA because they allow for calibration of instruments, validation, and quality control (QC) of methods and laboratories based on the traceability and comparability of measurement results. QC is the combination of the operational techniques and activities that are used to fulfill requirements for quality. Target and range-certified values may be generated from data produced by several laboratories by using different analytical methods or calculated from data obtained by the use of one analytical method. Statistical control limits are calculated from the historical results obtained during the analysis of the QC materials or validation data.
