New insights in carbohydrate-deficient transferrin analysis with capillary electrophoresis-mass spectrometry

Details

Serval ID
serval:BIB_366BF9C592A1
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
New insights in carbohydrate-deficient transferrin analysis with capillary electrophoresis-mass spectrometry
Journal
Forensic Science International
Author(s)
Kohler I., Augsburger M., Rudaz S., Schappler J.
ISSN
1872-6283 (Electronic)
ISSN-L
0379-0738
Publication state
Published
Issued date
2014
Peer-reviewed
Oui
Volume
243
Pages
14-22
Language
english
Notes
Publication types: JOURNAL ARTICLE
Abstract
Capillary zone electrophoresis (CZE) with UV detection has been widely used for the determination of carbohydrate-deficient transferrin (CDT), an indirect marker of the chronic alcohol consumption (≥60-80g/day). A commercially available method (CEofix? CDT kit), containing a bilayer anionic coating, allows for the analysis of CDT with a high resolution between transferrin (Tf) glycoforms with reduced protein adsorption onto the capillary wall. Although widely used in routine analysis, this procedure presents some limitations in terms of selectivity and sensitivity which may be overcome with mass spectrometry (MS). However, the available method is not MS-compatible due to the non-volatile coating as well as the phosphate and borate buffers present in the background electrolyte (BGE). This study firstly consisted in developing MS-compatible separation conditions, i.e., coating and BGE compositions. Numerous cationic, neutral, and anionic coatings were evaluated in combination with BGEs covering a broad range of pH values. A bilayer coating composed of a cationic layer of 10% polybrene (m/v) and an anionic layer of 10% dextran sulfate (m/v) combined with a BGE composed of 20mM ammonium acetate at pH 8.5 provided the best results in terms of glycoforms' resolution, efficiency, adsorption reduction, migration times' repeatability, and coating stability. The method was then transferred to CZE-MS after investigations of the electrospray ionization (ESI) source, equipped with a sheath-flow interface, and the time-of-flight (TOF/MS) parameters. A successful MS detection of tetrasialo-Tf was obtained during infusion, while the experiments highlighted the challenges and issues encountered with intact glycoprotein analysis by CZE-ESI-MS.
Keywords
Capillary coating, Capillary electrophoresis, Carbohydrate-deficient transferrin, Chronic alcohol consumption, Mass spectrometry
Pubmed
Web of science
Create date
28/04/2014 13:02
Last modification date
20/08/2019 14:24
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