title: On-line monitoring of pH junctions in capillary electrophoresis using Fourier transform infrared spectrometry.
abstract: Fourier transform mid-infrared spectroscopic detection is proposed as an on-line detection technique for the study of on-line preconcentration processes in capillary electrophoresis (CE). The molecule-specific information contained in mid-IR spectra can be used to directly determine the chemical compositions of individual zones and their boundaries. This paper reports on pH junctions employed in myoglobin analysis. On-line mid-IR detection allowed the shape of the sample peak to be monitored as well as the chemical compositions of the surrounding zones. From this information it was possible to obtain detailed insights into the actual chemical compositions of the individual zones governing the efficiency of the preconcentration technique applied. The principle of measurement outlined here can therefore also be regarded as a promising one for investigating other on-line preconcentration techniques, like stacking, sweeping, and pH junction-sweeping among others.
authors.affiliation: Institute for Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164, 1060, Vienna, Austria.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Quintás
authors.forename: Elena
authors.initials: E
authors.lastname: Nuñez
authors.forename: M
authors.initials: M
authors.lastname: Vellekoop
authors.forename: Bernhard
authors.initials: B
authors.lastname: Lendl