Author(s): Tang, J (Tang, Ji); Wu, HM (Wu, Huanming); Hu, JJ (Hu, Jun Jack); Yu, JC (Yu, Jiancheng); Zhang, JL (Zhang, Junliang); Wang, CL (Wang, Chenlu); Yin, T (Yin, Tao); Tang, KQ (Tang, Keqi)

Source: ANALYST Volume: 146 Issue: 1 Pages: 124-131 DOI: 10.1039/d0an01640c Published: JAN 7 2021

Abstract: Limited sample loading capacity is one of the major reasons that prevents the utility of capillary electrophoresis (CE) as a routine separation method as compared to liquid chromatography (LC). In our previous study, separation voltage polarity switching transient capillary isotachophoresis (PS-tCITP) was proposed. Both sample loading capacity and separation resolution could be improved using a single PS-tCITP instead of routine transient capillary isotachophoresis (tCITP). In this study, a detailed investigation on the optimization strategy of the PS-tCITP method was performed systematically. A possible mechanism of sample preconcentration in multiple PS-tCITP was first proposed to better understand the multiple PS-tCITP process. Several optimization experiments were then performed, including single PS-tCITP, paused PS-tCITP and multiple PS-tCITP, sequentially using a mixture of five peptides. By selecting an optimum polarity switching time, sample loading capacity of 100% capillary volume could be achieved in a single PS-tCITP. Introducing an additional pause between each polarity switching in a single PS-tCITP further improved the separation resolution. Experimental results showed a baseline separation of five selected peptide standards at 100% sample loading volume using a 100 min pause in a single PS-tCITP. To further improve separation efficiency while still maintaining 100% sample loading volume, a multiple PS-tCITP technique was developed through this study. Compared to the separation performance of the optimal single PS-tCITP at 100% sample loading volume with a 10 min pause, the separation window was improved by 54% and the peak capacity was improved by 48% in the optimal four PS-tCITP with the same sample loading volume and pause.

Accession Number: WOS:000607369300006

PubMed ID: 33104142

Author Identifiers:

Author        Web of Science ResearcherID        ORCID Number

Hu, Jun                  0000-0001-8866-9718

Zhang, Junliang         G-3307-2017         0000-0002-0997-1247

TANG, JI                  0000-0003-0364-1121

ISSN: 0003-2654

eISSN: 1364-5528

Full Text: https://pubs.rsc.org/en/content/articlelanding/2021/AN/D0AN01640C#!divAbstract