title: Determination and quantification of the emetic toxin cereulide from Bacillus cereus in pasta, rice and cream with liquid chromatography-tandem mass spectrometry.
abstract: A rapid and sensitive method has been developed for determination and quantification of cereulide in cream, rice and pasta. Samples are homogenised after addition of amylase to cooked rice and pasta, and cereulide is extracted with methanol. After the removal of water with methyl-tert butyl ether/hexane and evaporation until dryness, no further purification was required before analysis with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Recently, both cereulide and (13)C6-cereulide has become commercially available at high purities; hence, this method offers a more reliable quantification of positive samples than previous methods using valinomycin or in-house produced and purified cereulide as calibration standard. The introduction of amylase in the sample preparation improves both the extraction yield of cereulide from positive samples of starch-rich matrices such as pasta and rice, and the within-laboratory reproducibility of the analytical method. The LoQ of the method is 1.1 ng/g cereulide with RSDs ranging from 2.6% to 10%. The method is fully validated based on Commission Decision 2002/657/EC, suitable for routine analysis, and has been used to analyse samples from a cereulide food poisoning outbreak in a kindergarten in Norway. Cereulide production in different rice and pasta samples was investigated, showing that cereulide was unexpectedly produced by emetic Bacillus cereus in all eight pasta and rice samples.
authors: a Norwegian University of Life Sciences , NMBU School of Veterinary Science , Oslo , Norway.
authors: Helene Thorsen
authors: HT
authors: Rønning
authors: Tone Normann
authors: TN
authors: Asp
authors: Per Einar
authors: PE
authors: Granum
mesh_terms: D001409:Bacillus cereus; D002853:Chromatography, Liquid; D003611:Dairy Products / Q000032:analysis*; D047630:Depsipeptides / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis*; D005517:Foodborne Diseases; D006801:Humans; D009664:Norway; D012275:Oryza / Q000737:chemistry*; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry; D014908:Triticum / Q000737:chemistry*
chemical_list: D047630:Depsipeptides; C089294:cereulide
keywords: LC-MS/MS; cereulide; emetic Bacillus cereus