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Separation of ternary systems of hydrophilic ionic liquid with miscible organic compounds by RPLC with refractive index detection
Author(s) -
Zhang Dongli,
Deng Yuefeng,
Li Chuanbi,
Chen Ji
Publication year - 2008
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200700634
Subject(s) - ionic liquid , refractive index , ternary operation , chromatography , chemistry , ionic bonding , analytical chemistry (journal) , materials science , organic chemistry , ion , optoelectronics , computer science , programming language , catalysis
A rapid and simple analytical method was developed for the simultaneous and quantitative determination and separation of hydrophilic imidazolium ionic liquids (ILs) (1‐butyl‐3‐methylimidazolium chloride, [C 4 mim]Cl; 1‐hexyl‐3‐methylimidazolium chloride, [C 6 mim]Cl; 1‐octyl‐3‐methylimidazolium chloride, [C 8 mim]Cl; 1‐allyl‐3‐methylimidazolium chloride, [Amim]Cl; or 1‐allyl‐3‐methylimidazolium bromide, [Amim]Br) with miscible ethyl acetate and EtOH and their mixtures using reverse phase liquid chromatography coupled with refractive index detection (RPLC–RI). The influence of 60 to 100% (volume percentage) methanol in the mobile phase on the IL systems ([C 4 mim]Cl, [C 6 mim]Cl, [C 8 mim]Cl, [Amim]Br, or [Amim]Cl)‐ethyl acetate‐EtOH was investigated. The optimum mobile phase for the system [C 8 mim]Cl‐ethyl acetate‐EtOH, [C 4 mim]Cl‐ethyl acetate‐EtOH, [Amim]Br‐ethyl acetate‐EtOH and [Amim]Cl‐ethyl acetate‐EtOH was methanol/water (60:40, v/v), and methanol/water (70:30, v/v) for [C 6 mim]Cl‐ethyl acetate‐EtOH. Under optimum mobile phase conditions for each system, the RSD of the retention time ranged from 0.02 to 0.04%, and the RSDs of the peak area percent ranged from 0.23 to 1.85%, which showed good reproducibility of the RPLC‐RI method. The RPLC‐RI method can determine IL, ethyl acetate, and EtOH simultaneously in 5 min, and the analytes, especially IL, can be eluted completely. The results show that the RPLC‐RI method can be used to separate and determine ILs in mixtures with organic compounds simultaneously and quantitatively.