Analysis of oxybutynin and N-desethyloxybutynin in human urine by dispersive liquid–liquid microextraction (DLLME) and capillary electrophoresis (CE) - Moreira, Bruna Juliana; Borges, K. B; Oliveira, Anderson Rodrigo Moraes de; Gaitani, Cristiane Masetto de (Analytical Methods, 2015)