Nonaqueous CE using contactless conductivity detection and ionic liquids as BGEs in ACN

Abstract

N,N'-Alkylmethylimidazolium cations have been separated in NACE when one of the N,N'-dialkylimidazolium salts (ionic liquids (ILs)) was used as an electrolyte additive to the organic solvent separation medium. The separated species were 1-methyl-, 1-ethyl-, 1-butyl-, 1-octyl-, 1-decyl-3-methylimidazolium and N-butyl-3-methylpyridinium cations and BGE composed of 1-ethyl-3-methylimidazolium ethylsulfate or 1-butyl-3-methylimidazolium trifluoroacetate [BMIm][FAcO] (A6; B2) diluted in ACN. It was demonstrated that contactless conductivity detection (CCD) may be applied to monitoring the separation process in nonaqueous separation media, allowing to use the UV light-absorbing imidazolium-based electrolyte additives. There could be marked three concentration regions of added ILs; at first ionic strength of BGE below 1-2 mM, and then the actual electrophoretic mobility of analytes rises from 0. At concentrations above 1-2 mM, the added IL facilitated separation. In concentration region of 1-20 mM, the actual electrophoretic mobility of analyzed imidazolium cations was increasing with decrease in separation medium ionic strength. At higher concentrations of BGE (above 30 mM), the conductivity of the separation media became too high for this detector. Some organic dyes were also successfully separated and detected by contactless conductivity detector in a 20 mM A6 separation electrolyte in ACN.

Capillary electrophoretic analysis of neutral carbohydrates using ionic liquids as background electrolytes

“…They are serving as components of BGEs for CE: analysis of dyes [27] and phenols [28,29] using nonaqueous BGEs and analysis of flavonoids [30] using aqueous BGEs. Moreover, isotachophoresis [31] and nonaqueous CE [32] is used for determination of ILs.…”

The use of novel ionic liquid‐in‐water microemulsion without the addition of organic solvents in a capillary electrophoretic system

“…Because of intriguing physicochemical properties, IL has shown tremendous applications in various analytical fields, such as sample preparation [18], electrochemistry [19], chromatography [20], spectroscopy [21] and an unorthodox matrix for analysis [22]. Among them, increasing number of investigations by employing IL in CE have provided significant advantages in the sample treatment [23], chiral analysis [24,25], the use of PSP [26,27], the addition of chemical modifier [28] and the support coating [29]. Interesting, IL-based microemulsions have triggered enormous interest among scientists when IL was used as a substitute for water, oil or surfactant.…”

Determination of metal content in superoxide dismutase enzymes by capillary electrophoresis†

“…Nowadays ILs have numerous chemical applications and are used in various analytical techniques including HPLC, GC, and MS . ILs also serve as BGE additives in CE in the analysis of different samples .…”