Figure 3: Effect of mobile phase pH on the retention of sulfaquinoxaline sodium (Sulf) (20 g/ml), vitamin K3 (Vit K) (10 g/ml), and amprolium hydrochloride (Ampro) (20 g/ml). Mobile phase consisting of ACN and 0.2M NH4AC solution (80:20; v/v); flow rate=0.5 ml/min; ?=263 nm; the pH of the mobile phase is as shown in the figure.