@article{gomes_padilha_moreira_dias filho_gushikem_1998,  title={Determination of Metal Ions in Fuel Ethanol after Preconcentration on 5-Amino-1,3,4-Thiadiazole-2-Thiol Modified Silica Gel},  volume={9},  ISSN={0103-5053},  url={https://doi.org/10.1590/S0103-50531998000500015},  DOI={10.1590/S0103-50531998000500015},  number={5},  journal={Journal of the Brazilian Chemical Society},  publisher={Sociedade Brasileira de Química},  author={Gomes, Luis A. de Melo and Padilha, Pedro de Magalhães and Moreira, José Celso and Dias Filho, Newton L. and Gushikem, Yoshitaka},  year={1998},  month={Sep},  pages={494–498} }