title: Quantitative analysis of cereulide toxin from Bacillus cereus in rice and pasta using synthetic cereulide standard and 13C6-cereulide standard - a short validation study.
abstract: A single laboratory validation study of a rapid and sensitive quantitative method for the analysis of cereulide toxin produced by Bacillus cereus using ultra high performance liquid chromatography-electrospray-tandem mass spectrometry is presented. The analysis of this cyclic peptide toxin was validated for pasta and rice samples using a newly presented synthetic cereulide peptide standard, together with 13C6-cereulide that previously have not been commercially available. The use of cereulide standard was also compared to the most frequently used surrogate standard, the antibiotic valinomycin. The performance of the method was evaluated by analyzing spiked sample pools from different types of rice and pasta, as well as 21 individual rice and pasta samples from differently prepared meals. Inoculation of samples with three cereulide toxin-producing strains of Bacillus cereus was finally used to mimic naturally contaminated foods. The quantification range of the method was 1-500 ng/g (R2 = 0.999) and the limits of detection and quantification were 0.1 and 1 ng/g, respectively. The precision varied from 3% to 7% relative standard deviation and the trueness from -2% to +6% relative bias at different concentration levels in cooked rice and pasta.
authors.affiliation: Science Department, National Food Agency, Box 622, SE-751 26 Uppsala, Sweden. aida.zuberovic.muratovic@slv.se.
authors.forename: Aida
authors.initials: A
authors.lastname: Zuberovic Muratovic
authors.affiliation: Science Department, National Food Agency, Box 622, SE-751 26 Uppsala, Sweden. rikard.troger@outlook.com.
authors.forename: Rikard
authors.initials: R
authors.lastname: Tröger
authors.affiliation: Science Department, National Food Agency, Box 622, SE-751 26 Uppsala, Sweden. kristina.granelli@slv.se.
authors.forename: Kristina
authors.initials: K
authors.lastname: Granelli
authors.affiliation: Science Department, National Food Agency, Box 622, SE-751 26 Uppsala, Sweden. karl-erik.hellenas@slv.se.
authors.forename: Karl-Erik
authors.initials: KE
authors.lastname: Hellenäs
mesh_terms: D001409:Bacillus cereus / Q000737:chemistry*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D047630:Depsipeptides / Q000032:analysis* / Q000633:toxicity; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D057230:Limit of Detection; D012275:Oryza / Q000382:microbiology*; D010456:Peptides, Cyclic / Q000032:analysis / Q000633:toxicity; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry
chemical_list: D047630:Depsipeptides; D010456:Peptides, Cyclic; C089294:cereulide