Investigation of the presence of endogenous prednisolone in equine urine by high-performance liquid chromatography mass spectrometry and high-resolution mass spectrometry.
Rapid Commun Mass Spectrom
; 26(8): 879-86, 2012 Apr 30.
Article
em En
| MEDLINE
| ID: mdl-22396023
ABSTRACT
RATIONALE After the detection of low concentrations of prednisolone in racehorse urine samples collected at Italian racetracks, a study was initiated to investigate the accuracy of the analytical protocol used and the possible endogenous origin of detected prednisolone. METHODS:
Multiple reaction monitoring (MRM) MS(2) acquisition with a triple quadrupole (n = 780) and full scan MS(2) and MS(3) (n = 180) acquisition with a linear ion trap were checked. As a further confirmation, ten urine samples were analysed by high-resolution mass spectrometry (HRMS).RESULTS:
The study showed the difficulty of identifying prednisolone, probably due to interfering compounds with the same molecular weight (360 Da) present in the matrix. The characteristic transitions for prednisolone were identified, both in MS(2) and MS(3), as the ions 187 and 280; the ion 295 was also used for identification. The concentrations detected with the triple quadrupole and the linear ion trap were not statistically different. The exact mass of prednisolone formiate (the adduct acting as a molecular ion) was identified by HRMS.CONCLUSIONS:
The very high frequency of prednisolone detection in the samples (78.5%), the low concentration of this steroid and, importantly, the narrow range of the 95% confidence limits (0.97-1.05 in MS(2) mode and 0.88-1.04 in MS(3) mode), could represent evidence that its presence is endogenous. In the light of these results, this hypothesis seems the most probable, even if further studies are required to confirm it. Furthermore, a microbiological origin (i.e. fermentation of cortisol after sample collection) could not be disregarded.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Prednisolona
/
Cromatografia Líquida de Alta Pressão
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Espectrometria de Massas por Ionização por Electrospray
/
Substâncias para Melhoria do Desempenho
Tipo de estudo:
Evaluation_studies
/
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article