Determination of ammonium and metal ions by capillary electrophoresis–potential gradient detection using ionic liquid as background electrolyte and covalent coating reagent
- 作者：Qin ; Weidong ; Li ; Sam Fong Yau
- 关键词：Ionic liquids ; Capillary zone electrophoresis
- 刊名：Journal of Chromatography A
- 出版年：2004
- 期刊代码：47_00219673
- 类别：ch
- 出版时间：September 10, 2004
- 卷：1048
- 期：2
- 页码：253-256
- 文件大小：88.4 K
摘要
A capillary zone electrophoresis (CZE)–potential gradient detection (PGD) method coupled with field-amplified sample injection was developed to determine alkali metal, alkaline-earth metal, nickel, lead and ammonium ions. The capillary surface was coated with dialkylimidazolium-based ionic liquid and thus the electroosmotic flow (EOF) of the capillary was reversed. The buffer composed of 7.5mM lactic acid, 0.6mM 18-crown-6, 12mM α-cyclodextrin (α-CD); it was adjusted to pH 4.0 by 1-hexyl-3-methylimidazolium hydroxide. The 11 cations were baseline separated within 14min with 5.1–18.9·104 plates (for 40-cm-long capillary) in separation efficiency, and the detection limits were in the range of 0.27–7.3ng/ml. The method showed good reproducibility in terms of migration time with RSD ≤ 0.90%for run-to-run and ≤1.65 for day-to-day assessment.