title: Semi-automated solid-phase extraction method for studying the biodegradation of ochratoxin A by human intestinal microbiota.
abstract: A simple and rapid semi-automated solid-phase (SPE) extraction method has been developed for the analysis of ochratoxin A in aqueous matrices related to biodegradation experiments (namely digestive contents and faecal excreta), with a view of using this method to follow OTA biodegradation by human intestinal microbiota. Influence of extraction parameters that could affect semi-automated SPE efficiency was studied, using C18-silica as the sorbent and water as the simplest matrix, being further applied to the matrices of interest. Conditions finally retained were as follows: 5-mL aqueous samples (pH 3) containing an organic modifier (20% ACN) were applied on 100-mg cartridges. After drying (9 mL of air), the cartridge was rinsed with 5-mL H(2)O/ACN (80:20, v/v), before eluting the compounds with 3 × 1 mL of MeOH/THF (10:90, v/v). Acceptable recoveries and limits of quantification could be obtained considering the complexity of the investigated matrices and the low volumes sampled; this method was also suitable for the analysis of ochratoxin B in faecal extracts. Applicability of the method is illustrated by preliminary results of ochratoxin A biodegradation studies by human intestinal microbiota under simple in vitro conditions. Interestingly, partial degradation of ochratoxin A was observed, with efficiencies ranging from 14% to 47% after 72 h incubation. In addition, three phase I metabolites could be identified using high resolution mass spectrometry, namely ochratoxin α, open ochratoxin A and ochratoxin B.
authors.affiliation: AgroParisTech, UMR Ingénierie, Procédés, Aliments, F-75005 Paris, France. valerie.camel@agroparistech.fr
authors.forename: Valérie
authors.initials: V
authors.lastname: Camel
authors.forename: Minale
authors.initials: M
authors.lastname: Ouethrani
authors.forename: Cindy
authors.initials: C
authors.lastname: Coudray
authors.forename: Catherine
authors.initials: C
authors.lastname: Philippe
authors.forename: Sylvie
authors.initials: S
authors.lastname: Rabot
mesh_terms: D000097:Acetonitriles; D000328:Adult; D000693:Anaerobiosis; D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007422:Intestines / Q000382:microbiology*; D016018:Least-Squares Analysis; D054892:Metagenome; D008875:Middle Aged; D009793:Ochratoxins / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction / Q000379:methods*
chemical_list: D000097:Acetonitriles; D009793:Ochratoxins; C025589:ochratoxin A; C032159:acetonitrile