title: Studies of pesticides by collision-induced dissociation, postsource-decay, matrix-assisted laser desorption/ionization time of flight mass spectrometry.
abstract: The use of collision-induced dissociation, postsource decay (CID-PSD) matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the analysis of small organic molecules is demonstrated. Three pesticides: paraquat, diquat, and difenzoquat were chosen for this study. The matrices 2,5-dihydroxybenzoic acid (DHB), alpha-cyano-4-hydroxycinnamic acid (alpha-CHCA), and sinapinic acid (SA) were selected to investigate the effect of the matrix on the CID-PSD MALDI spectra of these molecules. Alpha-CHCA and DHB were found to be appropriate matrices for the pesticides studied. Spectra for a given pesticide obtained from different matrices were compared with each other, and the differences between them are discussed. A comparison of CID-PSD MALDI with fast-atom bombardment MS/MS spectra is presented; the agreement of pesticide fragmentation patterns between the two methods indicates that CID-PSD MALDI MS is a reliable and efficient technique for structural elucidation of small molecules.
authors.affiliation: Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Cheng
authors.forename: D M
authors.initials: DM
authors.lastname: Hercules
mesh_terms: D003373:Coumaric Acids / Q000737:chemistry; D004178:Diquat / Q000737:chemistry*; D005841:Gentisates; D062385:Hydroxybenzoates / Q000737:chemistry; D013058:Mass Spectrometry; D015394:Molecular Structure; D010269:Paraquat / Q000737:chemistry*; D010575:Pesticides / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D003373:Coumaric Acids; D005841:Gentisates; D062385:Hydroxybenzoates; D010575:Pesticides; D011720:Pyrazoles; C007175:alpha-cyano-4-hydroxycinnamate; C031394:difenzoquat; C073734:sinapinic acid; D004178:Diquat; D010269:Paraquat; C010925:2,5-dihydroxybenzoic acid