Synthesis and characterization of mesoporous silica modified with purpald and its application in the preconcentration of Cu2+ and Cd2+ from aqueous samples through solid-phase extraction - Wondracek, Marcos Henrique Pereira; Jorgetto, Alexandre de Oliveira; Silva, Adrielli Cristina Peres da; Schneider, José Fabian; Pedrosa, Valber de Albuquerque; Saeki, Margarida Juri; Castro, Gustavo Rocha de (Separations, 2023)