Column: GP C18 ( 5 μm, 120 Å, 4.6 x 250 mm ) phase: Phosphate buffer pH 5.0 ( KH2PO42.0g dissolved by about 650mL water, add 15mL 0.5mol/L tetrabutylammonium hydroxide in methanol, 7mL1mol/L H3PO4solution and 270mL methanol, cool to room temperature, adjust to pH 5.0 by NH...