It is shown that some indolylalkylamines - N,N-dimethyltryptamine, 5methoxy-N,N-dimethyltryptamine and the related bases, 2-methyl-1,2,3,4-tetrahydro-beta-carboline and its 6-methoxy derivative- are each cleanly separable from their respective metho cation derivatives on a column of the neutral polystyrene resin, Porapak Q, using methanol-O.2 M ammonium hydroxide (1 :1) as the eluent. The method was applied to the isolation of the metho cations of N,N-dimethyltryptamine and 5-methoxy-N,N-dimethyltryptamine occasionally extracted from the pasture grass Phalaris tuberosa, together with the parent tertiary bases and others which are common constituents of the grass at all stages of its growth cycle. The metho cation of 5-methoxy-N,N-dimethyltryptamine was identified by paper electrophoresis and that of N,N-dimethyltryptamine by mass spectrometry.