title: Large-scale synthesis of isotopically labeled 13C2-tenuazonic acid and development of a rapid HPLC-MS/MS method for the analysis of tenuazonic acid in tomato and pepper products.
abstract: Tenuazonic acid is a fungal secondary metabolite that is produced by a number of  Alternaria  species and is therefore a natural contaminant of food and feed samples. This paper describes a new strategy for the efficient and economical large-scale synthesis of the isotopically labeled internal standard (13)C(2)-tenuazonic acid via a three-step procedure. Furthermore, a new reliable and quick method based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) cleanup is presented for the determination of tenuazonic acid in food and feed samples utilizing high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) by application of the stable isotope dilution analysis. This new method has a limit of detection (LOD) of 0.86 μg/kg and a limit of quantitation (LOQ) of 2.89 μg/kg. In total 26 tomato samples and 4 bell pepper samples from the German market were analyzed. Tenuazonic acid was found in each sample with levels from 3 to 2330 μg/kg.
authors.affiliation: Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster, Münster, Germany.
authors.forename: Lilia
authors.initials: L
authors.lastname: Lohrey
authors.forename: Stefanie
authors.initials: S
authors.lastname: Marschik
authors.forename: Benedikt
authors.initials: B
authors.lastname: Cramer
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Humpf
mesh_terms: D002247:Carbon Isotopes; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013720:Tenuazonic Acid / Q000032:analysis / Q000138:chemical synthesis* / Q000737:chemistry; D014675:Vegetables / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D013720:Tenuazonic Acid