Effect of three different mobile phase acid additives on the separation of Compound E and the chromatographic figures of merit on a 50 mm x 4.6 mm LARIHC CF6-RN column. Conditions: 60/40/0.2/0.3, MeOH/ACN/acid additive/TEA, acid additive in the mobile phase condition A; trifluoroacetic acid, B; formic acid, C; acetic acid, flow rate = 2.0 ml/min., detection λ = 280 nm.