30 μg/mL eletriptan, dofetilide and doxazosin in (A) BGE, (B) Ringer’s solution, and (C) Ringer’s solution with acid stacking. BGE and Ringer’s solution were injected for 12 and 10 s, respectively. Acid stacking was performed with injection of sample for 50 s followed by injection of acid for 80 s. Injection was performed electrokinetically at 5 kV. The BGE was 100 mM sodium acetate buffer, pH 4.75, with a separation performed at 20 kV.