title: Development and validation of a liquid chromatography-tandem mass spectrometry method for the simultaneous determination of nine corticosteroid residues in bovine liver samples.
abstract: A liquid chromatography tandem mass spectrometry (LC-MS/MS) confirmatory method for the simultaneous determination of nine corticosteroids in liver, including the four MRL compounds listed in Council Regulation 37/2010, was developed. After an enzymatic deconjugation and a solvent extraction of the liver tissue, the resulting solution was cleaned up through an SPE Oasis HLB cartridge. The analytes were then detected by liquid chromatography-negative-ion electrospray tandem mass spectrometry, using deuterium-labelled internal standards. The procedure was validated as a quantitative confirmatory method according to the Commission Decision 2002/657/EC criteria. The results showed that the method was suitable for statutory residue testing regarding the following performance characteristics: instrumental linearity, specificity, precision (repeatability and intra-laboratory reproducibility), recovery, decision limit (CCα), detection capability (CCβ) and ruggedness. All the corticosteroids can be detected at a concentration around 1 μg kg(-1); the recoveries were above 62% for all the analytes. Repeatability and reproducibility (within-laboratory reproducibility) for all the analytes were below 7.65% and 15.5%, respectively.
authors: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, B. Ubertini, Brescia, Italy. guglielmo.dusi@izsler.it
authors: Guglielmo
authors: G
authors: Dusi
authors: Mara
authors: M
authors: Gasparini
authors: Michele
authors: M
authors: Curatolo
authors: Walter
authors: W
authors: Assini
authors: Eros
authors: E
authors: Bozzoni
authors: Nadia
authors: N
authors: Tognoli
authors: Enrica
authors: E
authors: Ferretti
mesh_terms: D000305:Adrenal Cortex Hormones / Q000032:analysis* / Q000302:isolation & purification; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003903:Deuterium / Q000737:chemistry; D004350:Drug Residues / Q000032:analysis* / Q000302:isolation & purification; D008099:Liver / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000305:Adrenal Cortex Hormones; D012997:Solvents; D003903:Deuterium