peaks for 4-OH TAM, with a retentio

peaks for 4-OH TAM, with a retention time of 7.28 min and 7.63 min respectively. N-DMT had a retention time of11.09 min, and TAM had the longest retention time, of11.52min. This allowed determination of the molecules’ plasma concentrations in treated horses (Fig. 1b), which yielded differences between fortified plasma and plasma from treated horses. For instance, only one peak for 4-OH TAM was present in all treated animals. There were two chromatography peaks for EDF in fortified plasma, one of which was absent in treated animals; a third peak appears later in the run, with a retention time of 10.9 min. EDF plasma concentration was estimated from both peak mea- surements, since the mass spectrum matched those from the molecule standards (Fig. 2).