title: New approach via gene knockout and single-step chemical reaction for the synthesis of isotopically labeled fusarin c as an internal standard for the analysis of this fusarium mycotoxin in food and feed samples.
abstract: The gold standard for quantitation of contaminants with high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) is the use of isotopically labeled standards. Herein, we report a new strategy for the synthesis of isotopically labeled 21-d3-fusarin C via a genetically modified Fusarium strain, followed by a one-step derivatization reaction. Fusarin C is a Fusarium mycotoxin, which is mutagenic after metabolic activation. Its occurrence has been demonstrated recently in corn-based samples, but up to now, little is known about the contamination of other grain samples. To collect further data, the quantitation method was enhanced by application of the 21-d3-fusarin C and the use of a QTRAP 5500 mass spectrometer. This new method has a limit of detection (LOD) of 1 μg/kg, a limit of quantitation (LOQ) of 4 μg/kg, and a recovery rate of 99%. A total of 21 corn samples and 13 grain samples were analyzed, with resulting fusarin C levels varying from not detectable to 24.7 μg/kg.
authors.affiliation: Institute of Food Chemistry, and ‡Molecular Biology and Biotechnology of Fungi, Westfälische Wilhelms-Universität Münster , 48149 Münster, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Kleigrewe
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Niehaus
authors.forename: Philipp
authors.initials: P
authors.lastname: Wiemann
authors.forename: Bettina
authors.initials: B
authors.lastname: Tudzynski
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Humpf
mesh_terms: D000821:Animal Feed / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003978:Diazomethane / Q000737:chemistry; D005504:Food Analysis / Q000379:methods / Q000592:standards; D005670:Fusarium / Q000235:genetics* / Q000378:metabolism; D055786:Gene Knockout Techniques / Q000379:methods*; D005818:Genetic Engineering; D007553:Isotope Labeling / Q000379:methods*; D057230:Limit of Detection; D011090:Polyenes / Q000032:analysis* / Q000138:chemical synthesis* / Q000378:metabolism; D011760:Pyrrolidinones / Q000378:metabolism; D053719:Tandem Mass Spectrometry / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D003313:Zea mays / Q000737:chemistry / Q000382:microbiology
chemical_list: D011090:Polyenes; D011760:Pyrrolidinones; D003978:Diazomethane; C041403:fusarin C