z-logo
Premium
A novel method for effective field measurements in electrical field‐flow fractionation
Author(s) -
Merugu Srinivas,
Sant Himanshu J.,
Gale Bruce K.
Publication year - 2012
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.201100530
Subject(s) - electric field , field strength , field flow fractionation , analytical chemistry (journal) , voltage , materials science , capacitance , field (mathematics) , ionic strength , electrode , fractionation , chemistry , chromatography , electrical engineering , physics , mathematics , engineering , quantum mechanics , aqueous solution , magnetic field , pure mathematics
The electric field that drives separation and retention in electrical field flow fractionation ( ElFFF ) and cyclical electrical field‐flow fractionation ( CyElFFF ) is a complex function of many parameters such as carrier ionic strength and pH, voltage, channel dimensions, flowrate, and electrode material. Currently there is no accurate or in situ method to measure the field during system operation. This paper introduces a technique to measure the effective electric field during ElFFF and CyElFFF operation using transient electrical spikes. With this technique we can determine the relationship between changes in carrier conductivity and flowrate during a run and their combined effect on effective field and retention in ElFFF . This technique can also be used to measure the voltage drop due to double layer capacitance in CyElFFF and the variation in effective field with frequency of the applied field. The measured effective fields for the CyElFFF and DC ElFFF techniques are also tested with a high ionic‐strength buffer solution as carrier. For a high ionic‐strength buffer, DC ElFFF generates a near‐zero effective field (0.2% in 100 s), whereas CyElFFF can sustain much higher effective fields (∼8%) even at relatively high voltages. The ability to measure the effective field allows for experiments to provide better data and for tuning and optimization of the separation run.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here