Preparation and Application of Cation Exchange Column Based on Hydrophilic Monodisperse Polymer Resins
A new weakly acidic cation stationary phase was synthesized by chemical modification of 5.0 μm monodisperse macroporous hydrophilic poly(glycidylmethacrylate-co-ethylenedimethacrylate)(PGMA/EDMA)beads.Its chromatographic properties were evaluated by conductivity detector for separation of alkali metals(Li+,Na+ and K+),ammonium(NH+4),alkaline earth metals(Mg2+ and Ca2+),and organic amines.The common mono and divalent cations in a single isocratic run can be separated by the elution with 7 mmol/L methyl vitriol at 1.0 mL/min.The organic amines were separated in 10 min by the elution with 3.5 mmol/L methyl vitriol and 5% acetonitrile.Under the experiment conditions,the linear range and detection limit of six cations were determined.The results showed that the six cations had good linear relationship and low detection limit.The influence of the eluent type,concentration and the flow rate for the separation of six cations was investigated.The column was used for the separation of inorganic cations from Cassia tea with only one step,four cations could be separated in 20 min.The recoveries of four cations were between 96% and 107%.In comparison with the IonPacCS12A cation exchanger column for separation of inorganic cations,the effect of resolution is almost same and the analysis time has been shorten to 44 min.