Gas chromatographic analysis of dimethyltryptamine and 'beta'-carboline alkaloids in ayahuasca, an Amazonian psychoactive plant beverage - Pires, Ana Paula Salum; Oliveira, Carolina Dizioli Rodrigues de; Moura, Sidnei; Dorr, Felipe Augusto; Silva, Wagner Abreu E.; Yonamine, Maurício (Phytochemical Analysis, 2009)