Carbon nanotubes-A resin for electrochemically modulated liquid chromatography

Abstract

Electrochemically modulated liquid chromatography is a special form of ion exchange chromatography in which the separation process is controlled by applying an electric potential to the stationary phase. This form of chromatography has so far only been applied in research studies. The present study shows that multiwalled carbon nanotubes are an effective resin material for an electrochemically modulated chromatography process. The experiments are carried out in a newly designed column that enables the packing of nanomaterials. We investigate the influence of the applied potential on the retention and elution of maleic acid, determine the dynamic binding capacity, and calculate the utilization degree of the electrical charge in the adsorption process. Moreover, the stability of the resin and the membrane over more than 200 working hours are presented. In addition to the stability, their sturdiness and inexpensive price are important qualities that make multiwalled carbon nanotubes interesting for application as the stationary phase in an electrochemically driven process. The investigated chromatography technique represents a promising separation process for future applications as a preparative step in biotechnology as well as other life science fields.

A Carbon Nanotube Packed Bed Electrode for Small Molecule Electrosorption: An Electrochemical and Chromatographic Approach for Process Description

“…The work presented here was carried out entirely in a self-designed PCC column based on the example of Brammen et al [28]. As stationary phase material, MWCNTs (CNT-K, Future Carbon GmbH, 95448 Bayreuth, Germany) with an outer diameter of 20-40 nm and a density of 2.1 g/cm 3 were packed in a curled, strong cation exchange membrane (CMI-7000, Membranes International Inc., Ringwood, NJ 07456, USA).…”

“…Brammen et al [28] developed a three-electrode column setup, with a bed volume of approximately 10 mL, and used Baytubes C150P carbon nanotubes as a stationary phase material. They confirmed that these MWCNTs, with excellent electrical, chemical and mechanical properties, are suitable and offer decisive advantages for PCC.…”

“…We describe the interaction of the electrode with charged molecules and the process performance under electrical potential. Based on the work of Brammen et al [28], and due to the fact that Baytubes C150P (Bayer Materials Science AG, Germany) are no longer commercially available, we establish a new type of non-functionalized, low-cost and easily accessible MWCNT (CNT-K, Future Carbon GmbH, Germany) as a resin and closely examine several processing features. Accordingly, the specific material properties of the CNT-K are analyzed, and the particulate electrode is described using a combination of chromatographic and electrochemical methods.…”

Iron Oxide Nanoparticles: Multiwall Carbon Nanotube Composite Materials for Batch or Chromatographic Biomolecule Separation

“…Thus, CNTs can be employed as hydrophobic interaction chromatography (HIC) resin which was demonstrated by Biesaga and Pyrzynska who were able to purify dicamba herbicides by the use of CNTs as chromatography resin [11]. For electrochemically modulated chromatography applications and the control of ion exchange by a potential switch, CNTs represent a very promising stationary phase material [12,13]. Furthermore, an application as extraction material for nonpolar compounds has been demonstrated [14].…”

Detection of peroxyl radicals from polluted air by free radical reaction combined with liquid chromatography signal amplification technique

“…In the search for new natural radical-scavenging reactive molecule, complex mixtures interferences are frequently encountered. The developed methods involving free radical reactive molecule assays coupled with HPLC were successfully developed [11][12][13][14][15][16][17][18][19][20][21][22][23].…”