Can neutral analytes be concentrated by transient isotachophoresis in micellar electrokinetic chromatography and how much?

Author(s)
Magdalena Matczuk, Lidia S. Foteeva, Maciej Jarosz, Mathea Sophia Galanski, Bernhard K. Keppler, Takeshi Hirokawa, Andrei R. Timerbaev
Abstract

Transient isotachophoresis (tITP) is a versatile sample preconcentration technique that uses ITP to focus electrically charged analytes at the initial stage of CE analysis. However, according to the ruling principle of tITP, uncharged analytes are beyond its capacity while being separated and detected by micellar electrokinetic chromatography (MEKC). On the other hand, when these are charged micelles that undergo the tITP focusing, one can anticipate the concentration effect, resulting from the formation of transient micellar stack at moving sample/background electrolyte (BGE) boundary, which increasingly accumulates the analytes. This work expands the enrichment potential of tITP for MEKC by demonstrating the quantitative analysis of uncharged metal-based drugs from highly saline samples and introducing to the BGE solution anionic surfactants and buffer (terminating) co-ions of different mobility and concentration to optimize performance. Metallodrugs of assorted lipophilicity were chosen so as to explore whether their varying affinity toward micelles plays the role. In addition to altering the sample and BGE composition, optimization of the detection capability was achieved due to fine-tuning operational variables such as sample volume, separation voltage and pressure, etc. The results of optimization trials shed light on the mechanism of micellar tITP and render effective determination of selected drugs in human urine, with practical limits of detection using conventional UV detector.

Organisation(s)
Department of Inorganic Chemistry
External organisation(s)
Hiroshima University, Warsaw University of Technology, Russian Academy of Sciences
Journal
Journal of Chromatography A
Volume
1345
Pages
212-218
No. of pages
7
ISSN
0021-9673
DOI
https://doi.org/10.1016/j.chroma.2014.04.022
Publication date
06-2014
Peer reviewed
Yes
Austrian Fields of Science 2012
106023 Molecular biology, 104002 Analytical chemistry
Keywords
ASJC Scopus subject areas
Analytical Chemistry, Biochemistry, Organic Chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/5cdf4bd5-d6ad-42fe-912a-05a1750dc73c