title: A corona discharge initiated electrochemical electrospray ionization technique.
abstract: We report here the development of a corona discharge (CD) initiated electrochemical (EC) electrospray ionization (ESI) technique using a standard electrospray ion source. This is a new ionization technique distinct from ESI, electrochemistry inherent to ESI, APCI, and techniques using hydroxyl radicals produced under atmospheric pressure conditions. By maximizing the observable CD at the tip of a stainless steel ESI capillary, efficient electrochemical oxidation of electrochemically active compounds is observed. For electrochemical oxidation to be observed, the ionization potential of the analyte must be lower than Fe. Ferrocene labeled compounds were chosen as the electrochemically active moiety. The electrochemical cell in the ESI source was robust, and generated ions with selectivity according to the ionization potential of the analytes and up to zeptomolar sensitivity. Our results indicate that CD initiated electrochemical ionization has the potential to become a powerful technique to increase the dynamic range, sensitivity, and selectivity of ESI experiments.
authors.affiliation: Proteomics and Mass Spectrometry Facility, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Lloyd
authors.forename: Sonja
authors.initials: S
authors.lastname: Hess
mesh_terms: D002851:Chromatography, High Pressure Liquid; D055664:Electrochemical Techniques / Q000379:methods*; D004563:Electrochemistry / Q000379:methods; D005296:Ferrous Compounds / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D017665:Hydroxyl Radical / Q000737:chemistry; D007460:Iodoacetamide / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D007477:Ions; D000075163:Metallocenes; D015394:Molecular Structure; D008970:Molecular Weight; D010084:Oxidation-Reduction; D017785:Photons; D011522:Protons; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D005296:Ferrous Compounds; D007477:Ions; D000075163:Metallocenes; D011522:Protons; D017665:Hydroxyl Radical; C004998:ferrocene; D007460:Iodoacetamide