General approach for certain quantitative calculations for Instance of the variance of reversible adsorption to the capillary wall in CE
(2009) In Analytical Chemistry 81(1). p.343348 Abstract
 Miniaturization of analytical separation methods offers several advantages, including short run times, high resolution, and high recovery of the sample constituents. To optimize these parameters, the reversible adsorption (to minimize loss in resolution), as well as the irreversible adsorption (to minimize loss of analytes) must be quantified. However, no useful equation is available for the calculation of the variance of reversible adsorption. Therefore, we have taken another approach to quantify the reversible interaction. The method is unique and important since no equation for calculation of this variance is required. Instead, two experiments are required, which are run under such conditions that the variance of a certain parameter has... (More)
 Miniaturization of analytical separation methods offers several advantages, including short run times, high resolution, and high recovery of the sample constituents. To optimize these parameters, the reversible adsorption (to minimize loss in resolution), as well as the irreversible adsorption (to minimize loss of analytes) must be quantified. However, no useful equation is available for the calculation of the variance of reversible adsorption. Therefore, we have taken another approach to quantify the reversible interaction. The method is unique and important since no equation for calculation of this variance is required. Instead, two experiments are required, which are run under such conditions that the variance of a certain parameter has the same numerical value in the two experiments (one with and without EOF), except for the variance of reversible adsorption. The approach is universal in the sense that it can be used for many different mathematical concepts and be modified to also cover certain functions other than a sum of parameters. We have also introduced a simple expression for the irreversible adsorption, which shows that the hydrophobic interaction from only two methyl groups in the coating gives rise to as much as 4050% loss of protein, and the width of the zones in the capillary with this coating was 815% larger compared to the zone width in the polyacrylamidecoated capillaries. The reproducibility in migration time, peak area, and peak width in two consecutive runs in capillaries with two methyl groups in the coating was very low, but in EOFfree polyacrylamidecoated capillaries extremely high, indicating that the reversible and irreversible adsorption of proteins to this coating is negligible. The scanning detector, frequently used in free zone electrophoresis in the 1960s1970s, gives true separation parameters and is, therefore, much preferable to the stationary detector used in most CE experiments, because this detector gives apparent separation parameters. (Less)
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http://lup.lub.lu.se/record/1235324
 author
 Farkas, Viktor; Rezeli, Melinda ^{LU} ; Végvári, Ákos ^{LU} ; Kilár, Ferenc and Hjertén, Stellan
 organization
 publishing date
 2009
 type
 Contribution to journal
 publication status
 published
 subject
 keywords
 electroosmotic flow, variance, EOF, plate number, coating, adsorption, microchip electrophoresis, capillary electrophoresis, mass spectrometry
 in
 Analytical Chemistry
 volume
 81
 issue
 1
 pages
 343  348
 publisher
 The American Chemical Society
 external identifiers

 pmid:19035645
 wos:000262113400049
 scopus:58149462262
 ISSN
 15206882
 DOI
 10.1021/ac8010457
 language
 English
 LU publication?
 yes
 id
 14845b2f1e9b42a292026903b361e115 (old id 1235324)
 date added to LUP
 20090108 09:33:41
 date last changed
 20180107 05:09:29
@article{14845b2f1e9b42a292026903b361e115, abstract = {Miniaturization of analytical separation methods offers several advantages, including short run times, high resolution, and high recovery of the sample constituents. To optimize these parameters, the reversible adsorption (to minimize loss in resolution), as well as the irreversible adsorption (to minimize loss of analytes) must be quantified. However, no useful equation is available for the calculation of the variance of reversible adsorption. Therefore, we have taken another approach to quantify the reversible interaction. The method is unique and important since no equation for calculation of this variance is required. Instead, two experiments are required, which are run under such conditions that the variance of a certain parameter has the same numerical value in the two experiments (one with and without EOF), except for the variance of reversible adsorption. The approach is universal in the sense that it can be used for many different mathematical concepts and be modified to also cover certain functions other than a sum of parameters. We have also introduced a simple expression for the irreversible adsorption, which shows that the hydrophobic interaction from only two methyl groups in the coating gives rise to as much as 4050% loss of protein, and the width of the zones in the capillary with this coating was 815% larger compared to the zone width in the polyacrylamidecoated capillaries. The reproducibility in migration time, peak area, and peak width in two consecutive runs in capillaries with two methyl groups in the coating was very low, but in EOFfree polyacrylamidecoated capillaries extremely high, indicating that the reversible and irreversible adsorption of proteins to this coating is negligible. The scanning detector, frequently used in free zone electrophoresis in the 1960s1970s, gives true separation parameters and is, therefore, much preferable to the stationary detector used in most CE experiments, because this detector gives apparent separation parameters.}, author = {Farkas, Viktor and Rezeli, Melinda and Végvári, Ákos and Kilár, Ferenc and Hjertén, Stellan}, issn = {15206882}, keyword = {electroosmotic flow,variance,EOF,plate number,coating,adsorption,microchip electrophoresis,capillary electrophoresis,mass spectrometry}, language = {eng}, number = {1}, pages = {343348}, publisher = {The American Chemical Society}, series = {Analytical Chemistry}, title = {General approach for certain quantitative calculations for Instance of the variance of reversible adsorption to the capillary wall in CE}, url = {http://dx.doi.org/10.1021/ac8010457}, volume = {81}, year = {2009}, }