A study of the in-column detection performance for chromatography separation

Abstract

This paper studies the in-column detection performance for chromatography separation. Numerical modelling was performed to investigate the detection efficiency of the electrodes that are suspended within a packed chromatography column. The results show that the density of the silica beads packed within the channel does not hinder the detection ability of the electrode. The findings have been further validated with experimental works. A 8 in-column electrode array provides the full separation progress traces of the five neurotransmitters and metabolites (adrenalin, dopamine, DOPAC, serotonin and 5-HIAA) within the column. From the in-column detection, better peak resolutions are developed though the separation column as compared to the conventional post column detection. The whole progress of the separation shows that good separation (Rs > 1) can be obtained at E5 (28.7 mm from column inlet), whereas baseline separation could be obtained at E8 (last in-column electrode) with Rs ≥ 1.5 within 60 minutes. The presented results suggest the packing materials within the column does not obstruct the efficiency of the electrodes but able to produce a good baseline separation detection as compared to conventional post column detection.

Advances in and prospects of microchip liquid chromatography

“…An interesting direction has been to incorporate elements along the wall of the channel to enable detection. A polyethylene terephthalate chip containing an array of electrodes embedded along an LC column wall was used for whole-column electrochemical detection of neurotransmitters [33]. For the separation of proteomic samples from cell extracts, a chip containing integrated EOF pumps (which are closed to enable pressure-driven flow) for gradient LC was used [34].…”

“…Improvements in both device robustness [24-26] and instrument integration [33-35,39,50] are enabling technology that will be required for high efficiency on-chip chromatographic separations. For low-cost separation techniques, monolithic stationary phases in polymeric chips can be implemented [42-50] and it is possible that further advances in embossing techniques to generate pillar array columns [61] could eventually lead to disposable, one-use chromatography columns.…”

Thermal analysis of wirelessly powered thermo-pneumatic micropump based on planar LC circuit

“…Over the past decade, Micro-electro-mechanical system (MEMS) technology in microfluidic system provides a wide range of application opportunities [1][2][3][4]. One promising area is in biomedical applications, including drug delivery and medical therapeutic devices.…”

A Concentric Ring Electrode for a Wall‐jet Cell in a Microfluidic Device

“…Electrochemical detection facilitates the construction of more‐compact or portable analytical systems containing microfluidic devices because compact instruments for detection that consume low power have recently become available , and the fabrication of an electrode onto a substrate is easily accomplished by common microfabrication techniques. Electrochemical detection is applicable to a wider range of substances than fluorometric detection ; hence, it has been applied to many liquid‐phase separation analysis systems on microfluidic platforms, such as microchip capillary electrophoresis and liquid chromatography (LC) .…”