title: Tylosin detection in animal feed by liquid chromatography-tandem mass spectrometry with enzymatic hydrolysis of the tylosin urea adduct.
abstract: When the use of tylosin as a feed additive was forbidden by Council Regulation 2821/98, the necessity of a chemical confirmation method for the monitoring of the ban was created. Recently a method was developed for the detection of tylosin in animal feed by means of LC-MS/MS. During the validation high deviating values for the decision limit, detection capability, and repeatability for tylosin in cattle feed were observed, and the presence of urea and the formation of a tylosin urea adduct (TUA) were suggested as possible explanations. In this study two hydrolysis approaches for the TUA adduct were compared, namely, a chemical hydrolysis and an enzymatic hydrolysis with urease. The latter yielded a more complete hydrolysis of urea and was used for further validation. The recovery increased by approximately 15-25% depending on the amount of urea present in the feed (0.5-2%). The decision limit and detection capability were hardly influenced by the enzymatic hydrolysis.
authors.affiliation: Laboratory of Food Analysis, Ghent University, Harelbekestraat 72, B-9000 Gent, Belgium. christof.vanpoucke@UGent.be
authors.forename: Christof
authors.initials: C
authors.lastname: Van Poucke
authors.forename: Fréderic
authors.initials: F
authors.lastname: Dumoulin
authors.forename: Kirsten
authors.initials: K
authors.lastname: De Keyser
authors.forename: Chris
authors.initials: C
authors.lastname: Elliott
authors.forename: Carlos
authors.initials: C
authors.lastname: Van Peteghem
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002853:Chromatography, Liquid; D005503:Food Additives; D006868:Hydrolysis; D013058:Mass Spectrometry; D015645:Tylosin / Q000032:analysis*; D014508:Urea / Q000032:analysis*; D014510:Urease / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D005503:Food Additives; D014508:Urea; D014510:Urease; D015645:Tylosin