Successful establishment of MEKC with electrochemiluminescence detection based on one functionalized ionic liquid

Abstract

Herein, one water-soluble functionalized ionic liquid, 1-butyl-3-methylimidazolium dodecyl sulfate ([BMIm(+)][C(12)H(25)SO(-) (4)]), was designed and its superiorities either used as supporting electrolytes or as additives for successful establishment of MEKC with electrochemiluminescence (ECL) detection (MEKC-ECL) method were investigated. Compared with the common supporting electrolytes such as phosphate solution, 1-butyl-3-methylimidazolium dodecyl sulfate solution used as running buffers led to greatly enhanced ECL intensities and column efficiencies for negative targets, a little increase for neutral-charge ones while maintained nearly unchanged for positive ones due to the electrostatic forces between the large cation BMIm(+) and the solutes and the hydrophobic interactions resulting from the large anion C(12)H(25)SO(-) (4). Moreover, resolution efficiency between analytes was significantly improved. As the existence of ionic liquid moiety, BMIm(+), accelerated the electron transfer at the electrode surface, the poisoning effect of long chain C(12)H(25)SO(-) (4) on the electrode surface was eliminated and reproducible ECL intensities with relative standard derivation of 1.02% (n=6) were obtained. The proposed novel MEKC-ECL system was again validated by the baseline separated two similar amino acids of proline and hydroxyproline with lower detection limits of 0.5 and 0.8 microM (S/N=3), respectively.

Recent novel MEKC applications to analyze free amino acids in different biomatrices: 2009–2010

“…Analysis of these extraterrestrial samples was very productive allowing the authors to detect a variety of biotic and abiotic amino acids, including chiral amino acids. The method proposed by Xu et al 35, based on the use of micellar electrokinetic chromatography with chemiluminescence detection (MEKC‐ECL) should also be mentioned here for its peculiarity. The functionalized water‐soluble ionic liquid 1‐butyl‐3‐methylimidazolium dodecyl sulfate (BDS) was used either as the supporting electrolyte or as an additive for successful separations of analytes with electro‐chemiluminescence detection.…”

Recent advances in amino acid analysis by CE

“…The LODs for L ‐His, L ‐Thr, and L ‐Tyr were 0.64, 0.84, and 0.30 μM ( S / N =2), respectively 31. 1‐Butyl‐3‐methylimidazolium dodecyl sulfate, a water‐soluble ionic liquid, was used for MEKC‐CL for baseline separation of proline and hydroxyproline with LODs of 0.5 and 0.8 μM ( S / N =3), respectively 32. Lin et al .…”

MEKC as a powerful growing analytical technique

“…Other detection approaches which have been hyphenated to MEKC, however, with fewer reported applications include: electrochemical detection 160, 219–224, FTIR detection 225, 226, and chemiluminescence detection 227–230.…”