EVALUATION OF THE EFFECTIVENESS OF PARTICIPATION IN PROFICIENCY TESTING PROGRAMS IN THE QUALITY CONTROL OF THE ANALYTICAL RESULTS IN THE DETERMINATION OF METALS AND SEMIMETALS IN WATER IN A PUBLIC HEALTH LABORATORY

Abstract

Proficiency Testing Programs (PTP) have as purpose to evaluate the performance of a laboratory against preestablished criteria using interlaboratory comparisons, as an external evaluation tool in the demonstration of the laboratory analytical reliability, besides being one of the requirements for the accreditation process. For analytical laboratories that work in the quality control of products and services intended for human consumption, obtaining reliable results is fundamental for its credibility and quality assurance. Results issued by the laboratories are evaluated by the Proficiency Testing providers using statistical approaches (z score, zeta score, normalized error, among others) to evaluate the effectiveness of their performances. The goal of this work was to evaluate the effectiveness of the participation of the Inorganic Contaminants Laboratory (ICL), that belongs to the Contaminants Division of the Adolfo Lutz Institute, in different PTP for metals and semimetals in water, from 2013 to 2018. The obtained results demonstrated the effectiveness of the continuous improvement in the execution of the analyzes performed by the ICL, and consequently the reliability of the analytical results. This work aims to disseminate, encourage and provide tools to analytical laboratories that act in the quality control of products and services destined to Public Health, to assist the implementation of corrective and preventive measures, allowing its continuous analytical improvement.