Sample preconcentration in open microchannels combined with MALDI-MS
2012 (English)In: Electrophoresis, ISSN 0173-0835, E-ISSN 1522-2683, Vol. 33, no 22, 3343-3350 p.Article in journal (Refereed) Published
In this work, a method for preconcentrating samples in 1 cm long, 50-150 μm wide open microchannels is presented. Platinum electrodes were positioned at the channel ends, voltage was applied, and charged analyte was preconcentrated at the oppositely charged side during continuous supply of sample. The preconcentration was initially studied in a closed system, where an influence on the analyte position from a pH gradient, generated by water electrolysis, was observed. In the open channel, the analyte distribution after preconcentration was evaluated using MALDI-MS with the channel as MALDI target. MALDI matrix was applied with an airbrush or by electrospray matrix deposition and by using the latter technique higher degrees of crystallization in the channels were obtained. After preconcentrating a 1 nM cytochrome c solution for 5 min, corresponding to a supplied amount of 1.25 fmol, a signal on the cathodic channel end could be detected. When a solution of cytochrome c trypsin digest was supplied, the peptides were preconcentrated at different positions along the channel depending on their charge.
Place, publisher, year, edition, pages
2012. Vol. 33, no 22, 3343-3350 p.
Electrospray deposition, MALDI-MS, Preconcentration, Silicon microchip
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:kth:diva-108041DOI: 10.1002/elps.201200129ISI: 000311303100013ScopusID: 2-s2.0-84869782576OAI: oai:DiVA.org:kth-108041DiVA: diva2:579424
FunderSwedish Research Council
QC 201212202012-12-202012-12-192016-09-30Bibliographically approved