Preparation and Application of Methacrylate-Based Cation-Exchange Monolithic Columns for Capillary Ion Chromatography
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- 作者：Yuji Ueki ; Tomonari Umemura ; Jinxiang Li ; Tamao Odake ; and Kin-ichi Tsunoda
- 刊名：Analytical Chemistry
- 出版年：2004
- 出版时间：December 1, 2004
- 年：2004
- 卷：76
- 期：23
- 页码：7007 - 7012
- 全文大小：115K
- 年卷期：v.76,no.23(December 1, 2004)
- ISSN：1520-6882
文摘
Polymer-based strong cation-exchange monolithic capillary columns with different capacities were constructedfor ion chromatography by radical polymerization ofglycidyl methacrylate (GMA) and ethylene dimethacrylatein a 250-
m-i.d. fused-silica capillary and its subsequentsulfonation based on ring opening of epoxides with 1 MNa2SO3. The cation-exchange capacities can easily andreproducibly be controlled in the range of up to 300equiv/mL by changing the immersion time of the epoxy-containing polymer in the Na2SO3 solution. The chromatographic performance of the produced monolithiccapillary columns was evaluated through the separationof a model mixture of common cations such as Na+, NH4+,K+, Mg2+, and Ca2+. As an example, these cations couldbe well separated from one another on a 15-cm-longcation-exchange monolithic column (column volume, 7.4L) with a capacity of 150 equiv/mL by elution with 10mM CuSO4. The pressure drop of this 15-cm column was~1 MPa at a normal linear velocity of 1 mm/s (a flow rateof 3 L/min), and the numbers of theoretical plates forthe cations were above 3000 plates/15 cm. This GMA-based cation-exchange monolithic column could withstand high linear velocities of at least 10 mm/s. Over aperiod of at least two weeks of continuous use, nosignificant changes in the selectivity and resolution wereobserved. The applicability of a flow rate gradient elutionand the feasibility of direct injection determination ofmajor cations in human saliva sample were also presented.
m-i.d. fused-silica capillary and its subsequentsulfonation based on ring opening of epoxides with 1 MNa2SO3. The cation-exchange capacities can easily andreproducibly be controlled in the range of up to 300equiv/mL by changing the immersion time of the epoxy-containing polymer in the Na2SO3 solution. The chromatographic performance of the produced monolithiccapillary columns was evaluated through the separationof a model mixture of common cations such as Na+, NH4+,K+, Mg2+, and Ca2+. As an example, these cations couldbe well separated from one another on a 15-cm-longcation-exchange monolithic column (column volume, 7.4L) with a capacity of 150 equiv/mL by elution with 10mM CuSO4. The pressure drop of this 15-cm column was~1 MPa at a normal linear velocity of 1 mm/s (a flow rateof 3 L/min), and the numbers of theoretical plates forthe cations were above 3000 plates/15 cm. This GMA-based cation-exchange monolithic column could withstand high linear velocities of at least 10 mm/s. Over aperiod of at least two weeks of continuous use, nosignificant changes in the selectivity and resolution wereobserved. The applicability of a flow rate gradient elutionand the feasibility of direct injection determination ofmajor cations in human saliva sample were also presented.