title: Direct Analysis of Xanthine Stimulants in Archaeological Vessels by Laser Desorption Resonance Enhanced Multiphoton Ionization.
abstract: Resonance enhanced multiphoton ionization spectroscopy (REMPI) generates simultaneous vibronic spectroscopy and fragment free mass spectrometry to identify molecules within a complex matrix. We combined laser desorption with REMPI spectroscopy to study organic residues within pottery sherds from Maya vessels (600-900 CE) and Mississippian vessels (1100-1200 CE), successfully detecting three molecular markers, caffeine, theobromine, and theophylline, associated with the use of cacao. This analytical approach provides a high molecular specificity, based on both wavelength and mass identification. At the same time, the high detection limit allows for direct laser desorption from sherd scrapings, avoiding the need for extracting organic constituents from the sherd matrix.
authors.affiliation: Department of Chemistry and Biochemistry, University of California Santa Barbara , Santa Barbara, California 93106, United States.
authors.forename: Shawn C
authors.initials: SC
authors.lastname: Owens
authors.affiliation: Department of Chemistry and Biochemistry, University of California Santa Barbara , Santa Barbara, California 93106, United States.
authors.forename: Jacob A
authors.initials: JA
authors.lastname: Berenbeim
authors.affiliation: Department of Chemistry and Biochemistry, University of California Santa Barbara , Santa Barbara, California 93106, United States.
authors.forename: Marshall R
authors.initials: MR
authors.lastname: Ligare
authors.affiliation: Department of Chemistry and Biochemistry, University of California Santa Barbara , Santa Barbara, California 93106, United States.
authors.forename: Lisa E
authors.initials: LE
authors.lastname: Gulian
authors.affiliation: Department of Chemistry and Biochemistry, University of California Santa Barbara , Santa Barbara, California 93106, United States.
authors.forename: Faady M
authors.initials: FM
authors.lastname: Siouri
authors.affiliation: Department of Chemistry and Biochemistry, University of California Santa Barbara , Santa Barbara, California 93106, United States.
authors.forename: Samuel
authors.initials: S
authors.lastname: Boldissar
authors.affiliation: Department of Anthropology, University of California Santa Barbara , Santa Barbara, California 93106, United States.
authors.forename: Stuart
authors.initials: S
authors.lastname: Tyson-Smith
authors.affiliation: Department of Anthropology, University of California Santa Barbara , Santa Barbara, California 93106, United States.
authors.forename: Gregory
authors.initials: G
authors.lastname: Wilson
authors.affiliation: MesoAmerican Research Center, University of California Santa Barbara , Santa Barbara, California 93106, United States.
authors.forename: Anabel
authors.initials: A
authors.lastname: Ford
authors.affiliation: Department of Chemistry and Biochemistry, University of California Santa Barbara , Santa Barbara, California 93106, United States.
authors.forename: Mattanjah S
authors.identifier: 0000-0001-5007-8074
authors.initials: MS
authors.lastname: de Vries