Ultra-fast gradient LC method for omeprazole analysis using a monolithic column: assay development, validation, and application to the quality control of omeprazole enteric-coated pellets - Borges, Keyller Bastos; Sánchez, Antonio José Macías; Pupo, Mônica Tallarico; Bonato, Pierina Sueli; Collado, Isidro González (Journal of AOAC International, 2010)