Graphene oxide coated capillary for chiral separation by CE

Abstract

This article describes a new application of graphene oxide (GO) in CE based on the coating of fused silica capillary for chiral separation. The coated capillary was characterized by SEM, energy dispersive X-ray spectroscopy, and Raman spectra. The results indicated that the capillary was coated with GO. Chiral separations were carried out in the GO-coated capillary for the ephedrine-pseudoephedrine (E-PE) isomers and β-methylphenethylamine (β-Me-PEA) isomers at the optimal buffer conditions without any chiral selector by CE. The precision and reproducibility of GO-coated capillary were investigated, and the RSDs of migration time (n = 6) for the E-PE isomers were 1.35-1.41%, and 0.97-3.50% for β-Me-PEA isomers, respectively. The LOD for E-PE isomers and β-Me-PEA isomers was 3 μM and 18 μM, respectively.

Determination of Catechins in Tea by Micellar Electrokinetic Chromatography With a Graphene Oxide-Coated Capillary

“…[43,48] In brief, a new uncoated capillary was rinsed with NaOH (0.1 M) for 30 min, rinsed with water for 5 min, and an amino group was introduced by reaction with 3-aminopropyltriethoxysilane solution (2% v= v) prepared in anhydrous acetone for 15 min. The capillary was flushed with water (5 min), and for 1 h with glutaraldehyde (10% v=v) dissolved in 50 mM borate buffer at pH 9.0.…”

“…Another strategy to improve the efficiency involves modification of the capillary. Fused silica capillaries have been coated by a variety of materials including single-walled carbon nanotubes, [37] multi-walled carbon nanotubes, [38,39] zirconia, [40] graphene, [41] graphene oxide, [42][43][44][45][46][47][48] and gold nanoparticles. [49] In this study, a graphene oxide-coated capillary was prepared and used for the determination of catechins in tea by MEKC with an acidic running buffer (pH 3.0).…”

Preparation and characterization of tentacle-type polymer stationary phase modified with graphene oxide for open-tubular capillary electrochromatography

“…Furthermore, the analytical time of the whole running process was much shorter than that on monolithic columns. In addition, it is worth mentioning that the results obtained on the separation of amino acids and E-PE isomers by capillary electrochromatography were better than other related researches [26,31,32] considering of the resolution, separation efficiency and peak shape. In a word, the polymer coated open tubular capillary column with GO immobilization displayed some relevant advantages such as simple and timesaving preparation procedure, high analytical efficiency and satisfactory repeatability.…”

“…Furthermore, due to its ultrahigh specific surface area and large delocalized -electron system which can afford a strong -stacking interaction, GO is regarded as a promising stationary phase material for chromatography separation. To date, GO has been extensively exploited as stationary phase for GC [20], HPLC [21,22] and CE (including CEC) [23][24][25][26][27][28][29]. Among these published articles, packed column was barely reported probably because there is difficulty in the packing of nanothickness GO into the cartridge/column format.…”

“…Nevertheless, monolithic column suffers from the drawback of time-consuming preparation process. In contrast, it is a convenient approach that the GO-coated open-tubular capillary column is prepared via covalent modification [24][25][26][27] or electrostatic assembly [28,29] method.…”