All liquids used were HPLC grade. Acetonitrile, orthophosphoric acid, ultrapure analytical grade type 1 water (r > 18 m/cm) and hydrochloric acid were obtained from Fisher Scientific (Loughborough, Leicestershire, UK). Disodium hydrogen phosphate was
All liquids used were HPLC grade. Acetonitrile, orthophosphoric acid, ultrapure analytical grade type 1 water (r > 18 m/cm) and hydrochloric acid were obtained from Fisher Scientific (Loughborough, Leicestershire, UK). Disodium hydrogen phosphate was