Simultaneous electrokinetic and hydrodynamic injection and sequential stacking featuring sweeping for signal amplification following MEKC during the analysis of rapamycin (sirolimus) in serum samples

Ilona Olędzka , Piotr Kowalski , Alina Plenis , Natalia Miękus-Purwin , Niels Grabow , Thomas Eickner , Tomasz Bączek


Simultaneous electrokinetic and hydrodynamic injection of rapamycin (sirolimus) with off-line and online sample preconcentration techniques and using MEKC has been studied. Compared to conventional hydrodynamic injection, a 168-fold improvement in the signal was obtained with a combination of simultaneous electrokinetic and hydrodynamic injectionand field enhanced sample injection in conjunction with a sweeping technique called sequential stacking featuring sweeping. However, the coupling of the developed electrophoretic method and solid-phase microextraction allowed the signal intensity to increasemore than 231 times. In this approach, the injection of the sample at negative polarity (anode at the detector end) into the capillary and the MEKC separation was achieved within 5 min using an electrolyte (composed of 10 mM sodium tetraborate and 40 mM SDS) when ultraviolet (UV) detection was performed at 280 nm. Thus, by combining the application of the sequential stacking featuring sweeping supported by the solid-phase microextraction clean-up procedure, the detection limit (LOD) for rapamycin in a serum sample was significantly decreased, and was set at 25 ng/mL. The proposed combined simultaneous electrokinetic and hydrodynamic injection with field enhanced sample injection –sweeping technique following MEKC separation of sirolimus in human serum could be an effective tool in biomedical and clinical applications.
Author Ilona Olędzka
Ilona Olędzka,,
, Piotr Kowalski
Piotr Kowalski,,
, Alina Plenis
Alina Plenis,,
, Natalia Miękus-Purwin (FB / DAHP)
Natalia Miękus-Purwin,,
- Department of Animal and Human Physiology
, Niels Grabow
Niels Grabow,,
, Thomas Eickner
Thomas Eickner,,
, Tomasz Bączek
Tomasz Bączek,,
Journal seriesElectrophoresis, ISSN 0173-0835, (A 30 pkt)
Issue year2018
Publication size in sheets0.5
Keywords in English rapamycin (sirolimus), sequential stacking featuring sweeping, serum samples, simultaneous electrokinetic and hydrodynamic injection, Solid-Phase Microextraction
ASJC Classification1308 Clinical Biochemistry; 1303 Biochemistry
Languageen angielski
Score (nominal)30
ScoreMinisterial score = 30.0, 30-09-2019, ArticleFromJournal
Publication indicators WoS Citations = 0; Scopus SNIP (Source Normalised Impact per Paper): 2017 = 0.703; WoS Impact Factor: 2017 = 2.569 (2) - 2017=2.298 (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.