title: Identification of ochratoxin A in food samples by chemical derivatization and gas chromatography-mass spectrometry.
abstract: The contamination of foods with ochratoxin A can be determined very sensitively by high-performance liquid chromatography (HPLC) with fluorescence detection. A novel procedure is described to confirm OA-positive results quantitatively down to the HPLC detection limit of 0.1 ppb. For this, ochratoxin A in the sample extract is converted into its O-methylochratoxin A methyl ester derivative, which is identified subsequently by gas chromatography-mass spectrometry negative-ion chemical ionization and multiple ion detection modes using the hexadeuterated O-methyl-d3-ochratoxin A methyl-d3 ester derivative as internal standard for quantification. In the analysis of more than 60 contaminated samples, the procedure was found to be very accurate.
authors.affiliation: Max von Pettenkofer-Institut des Bundesgesundheitsamtes, Berlin, Germany.
authors.forename: Y
authors.initials: Y
authors.lastname: Jiao
authors.forename: W
authors.initials: W
authors.lastname: Blaas
authors.forename: C
authors.initials: C
authors.lastname: Rühl
authors.forename: R
authors.initials: R
authors.lastname: Weber
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D009793:Ochratoxins / Q000032:analysis*; D013050:Spectrometry, Fluorescence
chemical_list: D009793:Ochratoxins; C025589:ochratoxin A