Separation of small inorganic anions using methacrylate-based anion-exchange monolithic column prepared by low temperature UV photo-polymerization

Abstract: A methacrylate-based anion-exchange monolithic column was prepared by a single-step UV photo-copolymerization of [2-(methacryloyloxy)ethyl]-trimethyl ammonium chloride, butylmethacrylate, and ethylene dimethacrylate at a low temperature of −15°C. The anion-exchange column exhibited good separation efficiency for the small inorganic anions of NO2 −, Br−, NO3 −, and I− in the isocratic mode. Under the conditions optimized using a mobile phase of 50% ACN containing 100mM of NaCl, the theoretical plate heights of the anions were within the range of 12.2–15.6μm (N, 64,000–82,000m−1; k, 0.2–1.6); and a value of 9.4μm (N, 110,000m−1) was achieved for t 0. The flow resistance of the column was acceptably low with a permeability of 2.7×10−13 m2. Fast gradient elution at a flow rate of 32mm/s resulted in rapid and precise separation of the inorganic anions of IO3 −, NO2 −, Br−, NO3 −, and I− within 20s. [Copyright &y& Elsevier]