title: Tissue-spray ionization mass spectrometry for raw herb analysis.
abstract: Tissue-spray ionization mass spectrometry is developed for the in situ chemical analysis of raw herbs under ambient conditions. We demonstrated that analyte molecules could be directly sprayed and ionized from solvent-wetted ginseng tissues upon the application of high electrical voltage to the tissue sample. Abundant phytochemicals/ metabolites, including ginsenosides, amino acids and oligosaccharides, could be detected from ginseng tissues when the tissue-spray experiments were conducted in positive ion mode. Thermally labile and easily hydrolyzed malonyl-ginsenosides were also detected in negative ion mode. The tissue-spray ionization method enables the direct detection of analytes from raw herb samples and preserves the sample integrity for subsequent morphological and/ or microscopic examination. In addition, this method is simple and fast for chemical profiling of wild-type and cultivated-type American ginsengs with differentiation.
authors.affiliation: Department of Chemistry and Open Laboratory of Chemical Biology of the Institute of Molecular Technology for Drug Discovery and Synthesis, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
authors.forename: Sharon Lai-Fung
authors.initials: SL
authors.lastname: Chan
authors.forename: Melody Yee-Man
authors.initials: MY
authors.lastname: Wong
authors.forename: Ho-Wai
authors.initials: HW
authors.lastname: Tang
authors.forename: Chi-Ming
authors.initials: CM
authors.lastname: Che
authors.forename: Kwan-Ming
authors.initials: KM
authors.lastname: Ng
mesh_terms: D000596:Amino Acids / Q000032:analysis; D004560:Electricity; D036145:Ginsenosides / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D009844:Oligosaccharides / Q000032:analysis; D005894:Panax / Q000737:chemistry* / Q000145:classification; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry* / Q000145:classification; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D018709:Statistics, Nonparametric
chemical_list: D000596:Amino Acids; D036145:Ginsenosides; D009844:Oligosaccharides