title: Development of a mass spectrometry sampling probe for chemical analysis in surgical and endoscopic procedures.
abstract: A sampling probe based on ambient desorption ionization was designed for in vivo chemical analysis by mass spectrometry in surgical and endoscopic procedures. Sampling ionization of analytes directly from tissue was achieved by sealing the sampling tip against the tissue surface without allowing leakage of the auxiliary gas used for desorption ionization. The desorbed charged species were transferred over a long distance (up to 4 m) through a flexible tube of internal diameter as small as 1/16 in. to the inlet of the mass spectrometer used for analysis. The conditions used for desorption electrospray ionization (DESI) were optimized to achieve biocompatibility for clinical applications while obtaining adequate efficiency for the analysis. This optimization involved the removal of high voltage and use of pure water as a spray solvent instead of the organic solvents or aqueous mixtures normally used. Improved sensitivity was achieved under these conditions by increasing the gas flow rate in the transfer tube. The destructive effect on tissue surfaces associated with typical desorption ionization was avoided by altering the local gas dynamics in the sample area without compromising the overall analysis efficiency.
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University , West Lafayette, Indiana 47907.
authors.forename: Chien-Hsun
authors.initials: CH
authors.lastname: Chen
authors.forename: Ziqing
authors.initials: Z
authors.lastname: Lin
authors.forename: Sandilya
authors.initials: S
authors.lastname: Garimella
authors.forename: Lingxing
authors.initials: L
authors.lastname: Zheng
authors.forename: Riyi
authors.initials: R
authors.lastname: Shi
authors.forename: R Graham
authors.initials: RG
authors.lastname: Cooks
authors.forename: Zheng
authors.initials: Z
authors.lastname: Ouyang
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism / Q000601:surgery; D004724:Endoscopy / Q000379:methods*; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000601:surgery; D013058:Mass Spectrometry / Q000379:methods*; D015335:Molecular Probes; D051381:Rats
chemical_list: D015335:Molecular Probes