title: Ionspray microchip.
abstract: An ionspray microchip is introduced. The chip is based on the earlier presented nebulizer microchip that consists of glass and silicon plates bonded together. A liquid inlet channel, nebulizer gas inlet, and nozzle are etched on the silicon plate and a platinum heater is integrated on the glass plate. The nebulizer microchip has been previously used in atmospheric pressure chemical ionization, atmospheric pressure photoionization, sonic spray ionization, and thermospray ionization modes. In this work we show that the microchip can be operated also in ionspray mode by introducing high voltage to the silicon plate of the microchip. The effects of operation parameters (voltage, nebulizer gas pressure, sample solution flow rate, solvent composition, and analyte concentration) on the performance of the ion spray microchip were studied. Under optimized conditions the microchip provides efficient ionization of small and large compounds and good quantitative performance. The feasibility of the ion spray microchip in liquid chromatography/mass spectrometry (LC/MS) was demonstrated by the analysis of tryptic peptides of bovine serum albumin.
authors.affiliation: Division of Pharmaceutical Chemistry, Faculty of Pharmacy, P.O. Box 56, FI-00014 University of Helsinki, Finland. jaroslav.pol@helsinki.fi
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Pól
authors.forename: Tiina J
authors.initials: TJ
authors.lastname: Kauppila
authors.forename: Sami
authors.initials: S
authors.lastname: Franssila
authors.forename: Tapio
authors.initials: T
authors.lastname: Kotiaho
authors.forename: Risto
authors.initials: R
authors.lastname: Kostiainen
mesh_terms: D000818:Animals; D001920:Bradykinin / Q000737:chemistry; D002417:Cattle; D056656:Lab-On-A-Chip Devices; D046208:Microchip Analytical Procedures / Q000379:methods; D009330:Nebulizers and Vaporizers; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism; D012815:Signal Processing, Computer-Assisted; D012825:Silicon / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation* / Q000379:methods; D013739:Testosterone / Q000737:chemistry; D014357:Trypsin / Q000378:metabolism; D014700:Verapamil / Q000737:chemistry
chemical_list: D010446:Peptide Fragments; D004364:Pharmaceutical Preparations; D012710:Serum Albumin, Bovine; D013739:Testosterone; D010984:Platinum; D014700:Verapamil; D014357:Trypsin; D001920:Bradykinin; D012825:Silicon