Determination of steroids in bovine hair: Validation of a microwave‐assisted chemical derivatization method using liquid chromatography–tandem mass spectrometry and in vivo studies. Issue 8 (30th June 2020)

• Record Type: Journal Article
• Authors: Rocha, Diego G.; Lana, Mary Ane G.; de Assis, Débora C.S.; Cançado, Silvana V.; Augusti, Rodinei; Faria, Adriana F.
• Is Part Of: Drug testing and analysis. Volume 12:Issue 8(2020)
• Page Start: 1078
• Page End: 1086
• Publication Date: 2020-06-30
• Subjects: animal experimentation -- microwave derivatization -- steroid esters -- validation; Drugs -- Analysis -- Periodicals; Drug testing -- Periodicals; Chemistry, Forensic -- Periodicals; 615.1901
• DOI: 10.1002/dta.2815
• Languages: English
• ISSNs: 1942-7603

Abstract

Abstract: Hair analysis has attracted great attention in the regulatory analysis of food‐producing animals, particularly due to the wider detection window of veterinary drugs in this matrix and also the possibility of confirming parent drugs with minimum metabolization. This work involved the development and validation of a quantitative liquid chromatography–tandem mass spectrometry method to determine 25 steroids and steroid esters in bovine hair. Sensitivity was improved using a fast and effective microwave‐assisted chemical derivatization with methoxyamine hydrochloride. The validation was conducted in accordance with the Decision 657/2002/EC guidelines. An animal experimentation procedure was performed on 12 bovine animals in which two commercial formulations containing boldenone undecylenate and testosterone propionate were administrated via intramuscular injections on the neck. The samples were collected for 78 days in which the detection of the administrated analytes was only observed near the application sites. For some of the monitored days, no analyte was detected on the neck area. Since the migration of the analytes was not observed in areas other than the application site, false‐negative results should be carefully considered when monitoring animal hair samples. Abstract : The developed method was applied to an animal experimentation procedure in cattle. A high rate of false‐negative results was obtained because the target analytes were concentrated on the application site area.