ABSTRACT
The validity and effectiveness of quality control procedures are reviewed here in light of the principles of analytical toxicology, and of the professional responsibility involved in awareness of the profound influence which analytical results have in the fields of health and social security. Regardless of the methods used, laboratory work should aim essentially at achieving a very high degree of reliability. Factors contributing to the 'quality' of analytical results and methods used to check their reliability are discussed here. The technical background and organization of internal and external quality control procedures are presented, with particular reference to educational aspects, and to the ways in which computer and internet technologies may be exploited for further improvement of the effectiveness of these procedures.
