Improvement of derivatized amino acid detection sensitivity in micellar electrokinetic capillary chromatography by means of acid-induced pH-mediated stacking technique

Szymon Dziomba , Adrian Bekasiewicz , Adam Prahl , Tomasz Bączek , Piotr Kowalski


Derivatization is a frequently used sample preparation procedure applicable to the enhancement of analyte detection sensitivity. Amino acids mostly require derivatization prior to electrophoretic or chromatographic analysis, especially if spectrophotometric detection is used. This study presents an on-line preconcentration technique for derivatized amino acids. The sensitivity of the method was improved by the utilization of the proposed acid-induced pH-mediated stacking mechanism. The method is demonstrated by preconcentration of amino acids labeled with 2,4-dinitrofluorobenzene. Use of optimized conditions for a large sample volume injection (40 s, 13.8 kPa) followed by electrokinetic injection of 0.1 M HCl (20 s, 10 kV) gave a 20- to 30-fold enhancement of sensitivity. The significance of the sweeping mechanism and pseudo-isotachophoresis for the on-line sample focusing and the influence of parameters on the preconcentration process were discussed. The applicability of the elaborated method was demonstrated using human urine samples.
Author Szymon Dziomba
Szymon Dziomba,,
, Adrian Bekasiewicz
Adrian Bekasiewicz,,
, Adam Prahl (FCh / DOCh / LChB)
Adam Prahl,,
- Laboratory of Chemistry of Biopolymers
, Tomasz Bączek
Tomasz Bączek,,
, Piotr Kowalski
Piotr Kowalski,,
Journal seriesAnalytical and Bioanalytical Chemistry, ISSN 1618-2642 [1618-2650, 0937-0633], (A 40 pkt)
Issue year2014
Publication size in sheets0.5
Keywords in Englishcapillary electrophoresis, human urine samples, on-line preconcentration techniques, stacking, sweeping
ASJC Classification1303 Biochemistry; 1602 Analytical Chemistry
Languageen angielski
LicenseOther; published final; Uznanie Autorstwa (CC-BY); with publication
Score (nominal)40
ScoreMinisterial score = 40.0, 04-04-2019, ArticleFromJournal
Ministerial score (2013-2016) = 40.0, 04-04-2019, ArticleFromJournal
Publication indicators WoS Citations = 8; Scopus SNIP (Source Normalised Impact per Paper): 2014 = 1.222; WoS Impact Factor: 2014 = 3.436 (2) - 2014=3.565 (5)
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* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.