title: Organic acid quantitation by NeuCode methylamidation.
abstract: We have developed a multiplexed quantitative analysis method for carboxylic acids by liquid chromatography high resolution mass spectrometry. The method employs neutron encoded (NeuCode) methylamine labels ((13)C or (15)N enriched) that are affixed to carboxylic acid functional groups to enable duplex quantitation via mass defect measurement. This work presents the first application of NeuCode quantitation to small molecules. We have applied this technique to detect adulteration of olive oil by quantitative analysis of fatty acid methyl amide derivatives, and the quantitative accuracy of the NeuCode analysis was validated by GC/MS. Currently, the method enables duplex quantitation and is expandable to at least 6-plex analysis.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.
authors.forename: Arne
authors.initials: A
authors.lastname: Ulbrich
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Bailey
authors.forename: Michael S
authors.initials: MS
authors.lastname: Westphall
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Coon
mesh_terms: D000143:Acids / Q000032:analysis*; D000577:Amides / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D009930:Organic Chemicals / Q000032:analysis*
chemical_list: D000143:Acids; D000577:Amides; D009930:Organic Chemicals