Strategies for internal quality control in antidoping analyses

Internal quality control (IQC) is one of the most important elements contributing to quality assurance in the laboratory. In this study, the strategy for the implementation of an IQC program to monitor performance of the analytical procedures used in an antidoping control laboratory is presented. Different IQC parameters have been defined according to the aim of the method (qualitative or quantitative, screening or confirmation). They are based on the analysis of control and calibration samples in each analytical batch and on the use of an internal standard in chromatographic methods. IQC parameters for chromatographic and immunological methods and the acceptance criteria used to check the quality control data obtained are described and discussed. These IQC procedures have been applied during routine antidoping analyses of more than 5000 samples per year in a laboratory accredited by the International Olympic Committee (IOC) and meeting the requirements of the quality standard ISO 17025.