Evaluating the efficacy of psychotropic pharmaceuticals often involves in-vivo animal experiments with repeated sampling of brain extracellular fluids for their neurochemical content. By using a microdialysis probe, any changes in the extracellular levels of biogenic amines and major metabolites as shown in Figure 1 can be monitored over time. This offers insights into the psychoactive nature of the drug candidate. Therefore, experimental samples must be repeatedly and accurately analyzed so that any possible changes of major neuroactive chemicals can be observed with reasonable temporal resolution. Rapid analytical techniques such as UHPLC with sensitive electrochemical detection provide advantages over traditional HPLC assays since the sampling rates can be increased due to shorter run times involved with analysis.