Separation of small inorganic anions using methacrylate-based anion-exchange monolithic column prepared by low...

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 NO(2)(-), Br(-), NO(3)(-), 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 12.2-15.6 μm (N, 64,000-82,000 m(-1); k, 0.2-1.6); and a value of 9.4 μm (N, 110,000 m(-1)) was achieved for t(0). The flow resistance of the column was acceptably low with a permeability of 2.7 × 10(-13) m(2). Fast gradient elution at a flow rate of 32 mm/s resulted in rapid and precise separation of the inorganic anions of IO(3)(-), NO(2)(-), Br(-), NO(3)(-), and I(-) within 20s.