title: Toward understanding the ionization of biomarkers from micrometer particles by bio-aerosol mass spectrometry.
abstract: The appearance of informative signals in the mass spectra of laser-ablated bio-aerosol particles depends on the effective ionization probabilities (EIP) of individual components during the laser ionization process. This study investigates how bio-aerosol chemical composition governs the EIP values of specific components and the overall features of the spectra from the bio-aerosol mass spectrometry (BAMS). EIP values were determined for a series of amino acid, dipicolinic acid, and peptide aerosol particles to determine what chemical features aid in ionization. The spectra of individual amino acids and dipicolinic acid, as well as mixtures, were examined for extent of fragmentation and the presence of molecular ion dimers, which are indicative of ionization conditions. Standard mixtures yielded information with respect to the significance of secondary ion plume reactions on observed spectra. A greater understanding of how these parameters affect EIP and spectra characteristics of bio-aerosols will aid in the intelligent selection of viable future biomarkers for the identification of bio-terrorism agents.
authors.affiliation: Department of Chemistry, University of California, Davis, California, USA.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Russell
authors.forename: Gregg
authors.initials: G
authors.lastname: Czerwieniec
authors.forename: Carlito
authors.initials: C
authors.lastname: Lebrilla
authors.forename: Herbert
authors.initials: H
authors.lastname: Tobias
authors.forename: David P
authors.initials: DP
authors.lastname: Fergenson
authors.forename: Paul
authors.initials: P
authors.lastname: Steele
authors.forename: Maurice
authors.initials: M
authors.lastname: Pitesky
authors.forename: Joanne
authors.initials: J
authors.lastname: Horn
authors.forename: Abneesh
authors.initials: A
authors.lastname: Srivastava
authors.forename: Matthias
authors.initials: M
authors.lastname: Frank
authors.forename: Eric E
authors.initials: EE
authors.lastname: Gard
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D000596:Amino Acids / Q000032:analysis / Q000737:chemistry; D015415:Biomarkers / Q000032:analysis* / Q000737:chemistry*; D023482:Bioterrorism; D007477:Ions / Q000737:chemistry; D013058:Mass Spectrometry; D008832:Microchemistry; D010446:Peptide Fragments / Q000737:chemistry; D010848:Picolinic Acids / Q000032:analysis / Q000737:chemistry
chemical_list: D000336:Aerosols; D000596:Amino Acids; D015415:Biomarkers; D007477:Ions; D010446:Peptide Fragments; D010848:Picolinic Acids; C004860:dipicolinic acid