|Abstract Title:||Control and Traceability of the Analytical Data: a Case Study of Environmental Mercury Speciation Laboratory|
|Presenter Name:||Jssica Ramos|
|Company/Institution:||CENTER FOR MINERAL TECHNOLOGY|
|Session:||Special Session - Metrological Traceability for mercury analysis and speciation|
|Co-Authors:||Jssica Ramos,Zuleica Castilhos,Lillian Domingos|
Abstract Information :
The CETEM's Environmental Mercury Speciation Laboratory (LEMA) is dedicated to the analysis of trace levels of total mercury (HgT) in environmental and biological matrices. HgT levels are analyzed by using atomic absorption spectrometry with graphite furnace. The present work is a case study of the LEMA quality system management, and includes the uncertainty estimation, validation and standardization of the analytical method, based on the ISO/IEC 17025: 2017 standard. The uncertainty estimation was performed by using the ?Guide for the Expression of Uncertainty in Measurements? method, which identify the most important uncertainties sources to the analytical results. In addition, the validation of the analytical method were performed by using some parameters and criteria, such as: selectivity, linearity, working range, limit of detection, limit of quantification and accuracy, trend and repeatability, following the guidelines of the Brazilian National Institute of Metrology, Standardization and Industrial Quality (INMETRO). The results of both procedures mentioned above were used to standardize the analytical methodology, which also includes the choice and use of the Certified Reference Material (CRM). The methodology was validated and the detection and the quantification limit were defined as 0,0005mg/kg and 0,0091mg/kg, respectively. The uncertainty estimation results evidence the high quality of the results produced by the LEMA. They are within the range of the uncertainty declared in the certificates of the CRMs used (0,020 ? 0,0021mg/kg), which are ones that most contribute to the uncertainty of the analytical results. A protocol has been defined for choosing the CRM according to the matrix and the sample concentration range, as a result of the uncertainty study. These procedures added to the Quality Manual elaborated by LEMA?staff show the commitment to guarantee the quality of the results produced by this lab.