Confiabilidade Metrológica: o caso da análise de DQO em um laboratório acadêmico.

• Autor(a) principal: Mendez, érica Andrade Carvalho
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/10939
• topic: Environmental Engineering; Metrology; Quality management system; Measurement uncertainty; Validation; COD; Engenharia Ambiental; Metrologia; Sistema de gestão da qualidade; Incerteza de medição; Validação; DQO; CNPQ::ENGENHARIAS

Since 2004, CONAMA - National Council for the Environment - through its Resolution No. 344, has demanded that the physical, chemical and biological environmental matrices are performed in environmental laboratories that have formally acknowledged their technical competence through accreditation granted by Inmetro. Since then, some Federal Units has adopted the same criteria for laboratories registration in their databases. With that, there was an increase in the number of accreditations: in 2002 there were 12 accredited laboratories and in 2012 were granted accreditation to 198 environmental laboratories. The adoption of ABNT NBR ISO / IEC 17025 as the standard of work, in addition to attend the existing laws, has the following advantages: customer satisfaction, continuous improvement and credibility of the lab, professional skills improvement and the gain of a broader market. Seeking to adapt to this reality, despite of all the difficulties inherent in the process of implementing the requirements of ABNT NBR ISO / IEC 17025 in university and research laboratories, the Laboratory of Sanitary Engineering - LES / DESMA - prioritized to determine the suitability of Chemical Oxygen Demand - COD to the technical requirements of ABNT NRB ISO / IEC 17025:2005, as a global indicator parameter of organic matter in wastewater and surface and be widely used in monitoring liquid effluent treatment stations and because this it can be determined by two different analytical techniques: colorimetry and spectrophotometry. Given this scenario, the objective of this study was to evaluate the performance of the methods 5220 B and 5220 D described by Standard Methods, using validation parameters of analytical methods. Both methods proved to be suitable for the intended use and the limit of quantification determined appeared to be compatible with the practiced with accredited laboratories. The uncertainties were calculated to quantify the quality of the result.