Colloidal graphite-assisted laser desorption/ionization MS and MSn of small molecules. 2. Direct profiling and MS imaging of small metabolites from fruits

TitleColloidal graphite-assisted laser desorption/ionization MS and MSn of small molecules. 2. Direct profiling and MS imaging of small metabolites from fruits
Publication TypeJournal Article
Year of Publication2007
AuthorsZhang H, Cha SW, Yeung ES
Journal TitleAnalytical Chemistry
Volume79
Pages6575-6584
Date PublishedSep
Type of ArticleArticle
ISBN Number0003-2700
Accession NumberISI:000249242900026
KeywordsDESORPTION-IONIZATION, FATTY-ACIDS, FLIGHT MASS-SPECTROMETRY, INTERMEDIATE-PRESSURE MALDI, LIQUID-CHROMATOGRAPHY, MALDI-TOF-MS, OXIDIZED CARBON NANOTUBES, POROUS SILICON, THIN-LAYER-CHROMATOGRAPHY, TISSUE-SECTIONS
Abstract

Due to a high background in the low-mass region, conventional MALDI is not as useful for detecting small molecules (molecular masses < 500 Da) as it is for large ones. Also, spatial inhomogeneity that is inherent to crystalline matrixes can degrade resolution in imaging mass spectrometry (IMS). In this study, colloidal graphite was investigated as an alternative matrix for laser desorption/ionization (GALDI) in IMS. We demonstrate its advantages over conventional MALDI in the detection of small molecules such as organic acids, flavonoids, and oligosaccharides. GALDI provides good sensitivity for such small molecules. The detection limit of fatty acids and flavonoids, in the negative-ion mode are in the low-femtomole range. Molecules were detected directly and identified by comparing the MS and MS/MS spectra with those of standards. Various fruits were chosen to evaluate the practical utility of GALDI since many types of small molecules are present in them. Distribution of these small molecules in the fruit was investigated by using IMS and IMS/Ms.

DOI10.1021/ac0706170
Alternate JournalAnal. Chem.