MOURA, M.; SANTANA, S. A. A. Preparation of in-house reference material of Fe, Ca, Ni, and Si in carbon samples from an aluminum industrial facility and the results of a proficiency test. Revista e-TECH: Tecnologias para Competitividade Industrial - ISSN - 1983-1838, [S. l.], v. 15, n. 2, 2022. DOI: 10.18624/etech.v15i2.1169. Disponível em: https://etech.sc.senai.br/revista-cientifica/article/view/1169. Acesso em: 14 mar. 2025.