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Rapid test by liquid chromatography/tandem mass spectrometry to evaluate equine urine reactivity towards 17 β ‐OH steroids
Author(s) -
Fidani Marco,
Casagni Eleonora,
Montana Marco,
Pasello Emanuela,
Pecoraro Chiara,
Gambaro Veniero
Publication year - 2006
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.2608
Subject(s) - chemistry , chromatography , epitestosterone , urine , nandrolone , mass spectrometry , tandem mass spectrometry , liquid chromatography–mass spectrometry , stanozolol , steroid , biochemistry , anabolism , hormone
Abstract Bacteria frequently found in equine urine samples may cause degradation of 17 β ‐OH steroids. A simple liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed to evaluate the microbiological contamination of equine urine as a marker of poor storage conditions. Norethandrolone was used as the internal standard, and the linearity, sensitivity, precision and accuracy of the method were evaluated. 17 β ‐OH oxidation was demonstrated for testosterone, nandrolone, trenbolone and boldenone, but did not occur in α ‐epimers such as α ‐boldenone and epitestosterone, demonstrating the stereoselectivity of the reaction. A rapid test was performed by spiking one of the four 17 β ‐OH steroids in samples of diluted equine urine. The steroids were transformed into their respective ketones in the presence of bacterial activity. The test allows direct injection of diluted samples into the LC/MS system, without the need for prior extraction. Results show that the best method of storage is freezing at −18°C. Urine specimens should be analyzed as soon as possible after thawing. This allows bacterial degradation of equine urine to be arrested temporarily, so that the urine can be used for qualitative or quantitative analysis of 17 β ‐OH steroids. Copyright © 2006 John Wiley & Sons, Ltd.