Detalhes do Artigo
[297590] The Challenge of Developing Certified Reference Materials of Carbon Dioxide to Establish Traceability to Greenhouse Gases Monitoring Analysis
Autores: Andreia de Lima Fioravante, Claudia Cipriano Ribeiro, Viviane Fernandes Mello, Cristiane Rodrigues Augusto Chelles Iglesias, Valnei Smarçaro da Cunha
Resumo: In recent years the need for the quality control, reliability and traceability of analytical results has been strongly emphasised. The increase in the concentration of carbon dioxide (CO2) in the atmosphere has led the scientific community to investigate the adverse effects on humanity and nature, including the greenhouse effect, which contributes to global warming and can lead to climate change, besides the risks associated with human health. Due to the importance of metrological issues in the current scenario, the Laboratory of Gas Analysis (Lanag) of the National Institute of Metrology, Quality and Technology (Inmetro), is involved in improving measurement capabilities to provide confidence level regarding greenhouse gases standards by developing the methodology of preparation of such primary standard gas mixtures through gravimetry. This paper describes the development of certified reference materials of carbon dioxide in atmospheric synthetic air that are used to monitor its concentration in the atmosphere. Considering the contributions from gravimetry preparation and its verification analysis by cavity ringdown spectroscopy (CRDS) the relative expanded uncertainty of the standard mixture of carbon dioxide was lower than 0.5 % for the range studied from 370 to 550 μmol/mol, which is comparable to the average of 0.25% relative uncertainties presented on international standards mixtures.