title: [Determination of the thyreostats in animal muscle tissue by matrix solid-phase dispersion (MSPD) and liquid chromatography-tandem mass spectrometry].
abstract: BACKGROUND
  The residues ofthyreostats must not be present in the edible animal tissues. The proposed in the EU minimum required performance limit (MPRL) in the animal tissues is 10 microg/kg. This implies the decision limit (CCalpha) and decision capability (CCbeta) of the analytical methods used for the determination of these compounds lower than 10 microg/kg.
  
  
  OBJECTIVE
  This study aimed at the development, basing on the literature data and own studies the analytical method allowing for the identification and quantification of five thyreostats: tapazole (TAP), thiouracil (TU), methylotiouracil (MTU), propylothiouracil (PTU) and phenylotiouracil (FTU)) in the bovine muscle tissue, which would meet the criteria set in the Commission Decision No 2002/657/EC.
  
  
  METHODS
  The developed method used liquid chromatography-tandem mass spectrometry (LC-MS/MS). The sample was extracted and cleaned using the matrix solid-phase dispersion (MSPD) method. The LC was equipped with column Luna C18 Phenomenex. Dimetylotiouracyl was used as internal standard. The samples were fortified at levels: 5, 10 and 20 microg/kg. The method was validated according to the criteria laid down in Commission Decision No. 2002/657/EC.
  
  
  RESULTS
  At the levels, mean relative recoveries was in the range 90 - 109% and repeatability (CV %) was less than 10%. Decision limit (CCalpha) and detection capability (CCbeta) calculated for all thyreostats were below the recommended minimum required performance limit (MRPL) - 10 microg/kg.
  
  
  CONCLUSIONS
  The developed and validated LC-ESI-MS/MS method allows for the identification and quantification of five thyreostats in the bovine muscle tissue in the quantities below 10 microg/kg. Analytical procedure meets the criteria of Commission Decision No 2002/657/EC.
authors.affiliation: Pracownia Badań Srodków Spozywczych, Zakład Higieny Weterynaryjnej, Białystok. rodziewicz@wiw.bianet.com.pl
authors.forename: Lech
authors.initials: L
authors.lastname: Rodziewicz
authors.forename: Jolanta
authors.initials: J
authors.lastname: Masłowiecka
mesh_terms: D000818:Animals; D013956:Antithyroid Agents / Q000032:analysis* / Q000302:isolation & purification; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004350:Drug Residues / Q000032:analysis* / Q000302:isolation & purification; D057230:Limit of Detection; D009132:Muscles / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction; D013552:Swine; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D013956:Antithyroid Agents