Frontal Affinity Chromatogram showing the displacement of 0.25 nM [3H]-Win 551212 (A) in the presence of 1% Zanthoxylum clavaherculis (B) at a flow rate of 50 ml min−1 and the mobile phase composed of ammonium acetate [10 mM, pH 7.4] and methanol (90 : 10, v/v). Reproduced with permission from Fig. 3, Moaddel et al., Anal. Biochem., 2011, 412, 85–91.