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Monitoring gradient profile on-line in micro- and nano-high performance liquid chromatography using conductivity detection

Citation

Zhang, M and Chen, A and Lu, JJ and Cao, C and Liu, S, Monitoring gradient profile on-line in micro- and nano-high performance liquid chromatography using conductivity detection, Journal of Chromatography A, 1460 pp. 68-73. ISSN 0021-9673 (2016) [Refereed Article]

Copyright Statement

2016 Published by Elsevier B.V.

DOI: doi:10.1016/j.chroma.2016.07.005

Abstract

In micro- or nano-flow high performance liquid chromatography (HPLC), flow-splitters and gradient elutions are commonly used for reverse phase HPLC separations. When a flow splitter was used at a high split-ratio (e.g., 1000:1 or higher), the actual gradient may deviate away from the programmed gradient. Sometimes, mobile phase concentrations can deviate by as much as 5%. In this work, we noticed that the conductivity (σ) of a gradient decreased with the increasing organic-solvent fraction (φ). Based on the relationship between σ and φ, a method was developed for monitoring gradient profile on-line to record any deviations in these HPLC systems. The conductivity could be measured by a traditional conductivity detector or a capacitively coupled contactless conductivity detector (C4D). The method was applied for assessing the performance of an electroosmotic pump (EOP) based nano-HPLC. We also observed that σ value of the gradient changed with system pressure; a = 0.0175ΔP (R2 = 0.964), where a is the percentage of the conductivity increase and ΔP is the system pressure in bar. This effect was also investigated.

Item Details

Item Type:Refereed Article
Keywords:Nano-flow high performance liquid chromatography; Gradient profile monitoring; Capacitively coupled contactless conductivity detector; Electroosmotic pump
Research Division:Chemical Sciences
Research Group:Analytical Chemistry
Research Field:Separation Science
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Chemical Sciences
Author:Zhang, M (Dr Min Zhang)
ID Code:114724
Year Published:2016
Web of Science® Times Cited:1
Deposited By:Chemistry
Deposited On:2017-02-24
Last Modified:2017-11-01
Downloads:0

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