1,3-Dialkylimidazolium-based room-temperature ionic liquids as background electrolyte and coating material in aqueous capillary electrophoresis

• Published in: Journal of Chromatography A Vol. 985; no. 1; pp. 447 - 454
• Main Authors: Qin, Weidong, Wei, Hongping, Li, Sam Fong Yau
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 24.01.2003
• Subjects: Alkali metals; Alkaline-earth metals; Dialkylimidazolium; Electrolytes - chemistry; Electrophoresis, Capillary - methods; Humans; Imidazoles - chemistry; Ions; Metal cations; Metals - analysis; Quaternary Ammonium Compounds - urine; Wine - analysis; Background electrolyte composition; Metal cations; Alkali metals; Dialkylimidazolium; Ionic liquids; Coated capillaries; Alkaline-earth metals; Room-temperature ionic liquids
• ISSN: 0021-9673
• DOI: 10.1016/S0021-9673(02)01844-7

The 1-ethyl-3-methylimidazolium (EMIM) cation was found to have constant mobility of 4.5×10 −4 cm 2 V −1 s −1 over the pH range of 3 to 11. The electroosmotic flow of bare silica capillary was reversed by the covalently bonded room-temperature ionic liquid (RTIL) coating. With run buffer of 5 m M EMIM (pH 8.5), NH 4 + in human urine was separated from the K + matrix and was detected to be 0.37±0.012%. K +, Na +, Li +, Ca 2+, Mg 2+, and Ba 2+ were baseline separated in RTIL-coated capillary with run buffer of 10 m M EMIMOH–acetic acid at pH 5, and the concentration of the above ions in a red wine were detected to be 907, 27.9, 0, 71.0, 83.4 and 31.1 μg/ml, respectively. The RTIL-coated capillary showed stable electroosmotic flow for at least 80 h in the run buffer.