Electrospray Ionization from an Adjustable Gap between two Silicon Chips
2009 (English)In: Journal of Mass Spectrometry, ISSN 1076-5174, E-ISSN 1096-9888, Vol. 44, no 2, 171-181 p.Article in journal (Refereed) Published
In this paper, a silicon chip - based electrospray emitter with a variable orifice size is presented. The device consists of two chips, with a thin beam elevating from the center of each of the chips. The chips are individually mounted to form an open gap of a narrow, uniform width between the top areas of the beams. The electrospray is generated at the endpoint of the gap, where the spray point is formed by the very sharp intersection between the crystal planes of the < 100 > silicon chips. Sample solution is applied to the rear end of the gap from a capillary via a liquid bridge, and capillary forces ensure a spontaneous imbibition of the gap. The sample solution is confined to the gap by means of a hydrophobic treatment of the surfaces surrounding the gap, as well as the geometrical boundaries formed by the edges of the gap walls. The gap width could be adjusted between 1 and 25 μm during electrospray experiments without suffering from any interruption of the electrospray process. Using a peptide sample solution, a shift toward higher charge states and increased signal-to-noise ratios was observed when the gap width was decreased. The limit of detection for the peptide insulin (chain B, oxidized) was approximately 4 nM. We also show a successful interfacing of the electrospray setup with capillary electrophoresis.
Place, publisher, year, edition, pages
2009. Vol. 44, no 2, 171-181 p.
Adjustable gap, Chip, Electrospray ionization, Emitter, Mass spectrometry, Nozzle
IdentifiersURN: urn:nbn:se:kth:diva-8438DOI: 10.1002/jms.1478ISI: 000264013300002PubMedID: 18946877ScopusID: 2-s2.0-59949093565OAI: oai:DiVA.org:kth-8438DiVA: diva2:13757
QC 20100913. Uppdaterad från Manuskript till Artikel (20100913)2008-05-132008-05-132010-11-12Bibliographically approved