title: Polyelectrolytes as new matrices for secondary ion mass spectrometry.
abstract: Significant enhancements in ion yields in time-of-flight secondary ion mass spectrometry (TOF-SIMS) are observed when water-soluble analytes are mixed with a polyelectrolyte, e.g., poly(diallyldimethylammonium chloride) or poly(sodium 4-styrenesulfonate), and then deposited in the layer-by-layer method on a surface. This previously unobserved effect is demonstrated for 5-chloro-8-methoxyquinoline appended diaza-18-crown-6, 5-(2-aminoethoxy)methyl-5-chloro-8-methoxyquinoline appended diaza-18-crown-6, acridine, 9-anthracenecarboxylic acid, and ferrocenecarboxylic acid. By optical ellipsometry film thicknesses range from ca. 5-20 angstroms. X-ray photoelectron spectroscopy shows significantly less analyte in the polyelectrolyte-analyte films than in the neat analytes. However, TOF-SIMS generally shows significant enhancements in ion yields from the polyelectrolyte films compared with either the neat compounds or the compounds solubilized with acid or base and then dried on a surface. These significant enhancements in ion yields also appear to extend to analyte fragments and cationized molecular species. Some enhancement is also observed for dried droplets of analytes mixed with a polyelectrolyte on surfaces.
authors.affiliation: Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA.
authors.forename: Yit-Yian
authors.initials: YY
authors.lastname: Lua
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.forename: Craig A
authors.initials: CA
authors.lastname: Pew
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: W Jonathan J
authors.initials: WJ
authors.lastname: Fillmore
authors.forename: R Todd
authors.initials: RT
authors.lastname: Bronson
authors.forename: Amarchand
authors.initials: A
authors.lastname: Sathyapalan
authors.forename: Paul B
authors.initials: PB
authors.lastname: Savage
authors.forename: Jed D
authors.initials: JD
authors.lastname: Whittaker
authors.forename: Robert C
authors.initials: RC
authors.lastname: Davis
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Linford
mesh_terms: D045424:Complex Mixtures / Q000032:analysis* / Q000737:chemistry*; D004573:Electrolytes / Q000032:analysis* / Q000737:chemistry*; D008567:Membranes, Artificial; D012996:Solutions; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods*; D013499:Surface Properties; D014867:Water / Q000032:analysis / Q000737:chemistry*
chemical_list: D045424:Complex Mixtures; D004573:Electrolytes; D008567:Membranes, Artificial; D012996:Solutions; D014867:Water