Insights into head-column field-amplified sample stacking: Part II. Study of the behavior of the electrophoretic system after electrokinetic injection of cationic compounds across a short water plug.

Sesták, Jozef; Thormann, Wolfgang (2017). Insights into head-column field-amplified sample stacking: Part II. Study of the behavior of the electrophoretic system after electrokinetic injection of cationic compounds across a short water plug. Journal of chromatography A, 1512, pp. 124-132. Elsevier Science 10.1016/j.chroma.2017.06.073

[img] Text
wt258-Head-column FASS part II.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (841kB) | Request a copy

Part I on head-column field-amplified sample stacking comprised a detailed study of the electrokinetic injection of a weak base across a short water plug into a phosphate buffer at low pH. The water plug is converted into a low conductive acidic zone and cationic analytes become stacked at the interface between this and a newly formed phosphoric acid zone. The fundamentals of electrokinetic processes occurring thereafter were studied experimentally and with computer simulation and are presented as part II. The configuration analyzed represents a discontinuous buffer system. Computer simulation revealed that the phosphoric acid zone at the plug-buffer interface becomes converted into a migrating phosphate buffer plug which corresponds to the cationically migrating system zone of the phosphate buffer system. Its mobility is higher than that of the analytes such that they migrate behind the system zone in a phosphate buffer comparable to the applied background electrolyte. The temporal behaviour of the current and the conductivity across the water plug were monitored and found to reflect the changes in the low conductivity plug. Determination of the buffer flow in the capillary revealed increased pumping caused by the mismatch of electroosmosis within the low conductivity plug and the buffer. This effect becomes elevated with increasing water plug length. For plug lengths up to 1% of the total column length the flow quickly drops to the electroosmotic flow of the buffer and simulations with experimentally determined current and flow values predict negligible band dispersion and no loss of resolution for both low and large molecular mass components.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Service Sector > Institute for Infectious Diseases > Laboratory for Clinical Pharmacology

UniBE Contributor:

Sesták, Jozef and Thormann, Wolfgang

ISSN:

0021-9673

Publisher:

Elsevier Science

Language:

English

Submitter:

Wolfgang Thormann

Date Deposited:

22 Feb 2018 14:03

Last Modified:

04 Nov 2019 22:15

Publisher DOI:

10.1016/j.chroma.2017.06.073

PubMed ID:

28712552

Uncontrolled Keywords:

Capillary electrophoresis Computer simulation Electrohydrodynamics Electrokinetic injection Head-column field-amplified sample stacking Water plug

BORIS DOI:

10.7892/boris.108295

URI:

https://boris.unibe.ch/id/eprint/108295

Actions (login required)

Edit item Edit item
Provide Feedback