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Quantitation of 17@b-nandrolone metabolites in boar and horse urine by gas chromatography-mass spectrometry [An article from: Analytica Chimica Acta]
Book Details
Author(s)M. Roig, J. Segura, R. Ventura
PublisherElsevier
ISBN / ASINB000PDTCIS
ISBN-13978B000PDTCI2
AvailabilityAvailable for download now
MarketplaceUnited States 🇺🇸
Description
This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
A method to quantify metabolites of 17@b-nandrolone (17@bN) in boar and horse urine has been optimized and validated. Metabolites excreted in free form were extracted at pH 9.5 with tert-butylmethylether. The aqueous phases were applied to Sep Pak C"1"8 cartridges and conjugated steroids were eluted with methanol. After evaporation to dryness, either enzymatic hydrolysis with @b-glucuronidase from Escherichia coli or solvolysis with a mixture of ethylacetate:methanol:concentrated sulphuric acid were applied to the extract. Deconjugated steroids were then extracted at alkaline pH with tert-butylmethylether. The dried organic extracts were derivatized with MSTFA:NH4I:2-mercaptoethanol to obtain the TMS derivatives, and were subjected to analysis by gas chromatography mass spectrometry (GC/MS). The procedure was validated in boar and horse urine for the following metabolites: norandrosterone, noretiocholanolone, norepiandrosterone, 5@b-estran-3@a, 17@b-diol, 5@a-estran-3@b, 17@b-diol, 5@a-estran-3@b, 17@a-diol, 17@a-nandrolone, 17@bN, 5(10)-estrene-3@a, 17@a-diol, 17@a-estradiol and 17@b-estradiol in the different metabolic fractions. Extraction recoveries were higher than 90% for all analytes in the free fraction, and better than 80% in the glucuronide and sulphate fractions, except for 17@a-estradiol in the glucuronide fraction (74%), and 5@a-estran-3@b, 17@a-diol and 17@bN in the sulphate fraction (close to 70%). Limits of quantitation ranged from 0.05 to 2.1ngmL^-^1 in the free fraction, from 0.3 to 1.7ngmL^-^1 in the glucuronide fraction, and from 0.2 to 2.6ngmL^-^1 in the sulphate fraction. Intra- and inter-assay values for precision, measured as relative standard deviation, and accuracy, measured as relative standard error, were below 15% for most of the analytes and below 25%, for the rest of analytes. The method was applied to the analysis of urine samples collected after administration of 17@bN laureate to boars and horses, and its suitability for the quantitation of the metabolites in the three fractions has been demonstrated.
Description:
A method to quantify metabolites of 17@b-nandrolone (17@bN) in boar and horse urine has been optimized and validated. Metabolites excreted in free form were extracted at pH 9.5 with tert-butylmethylether. The aqueous phases were applied to Sep Pak C"1"8 cartridges and conjugated steroids were eluted with methanol. After evaporation to dryness, either enzymatic hydrolysis with @b-glucuronidase from Escherichia coli or solvolysis with a mixture of ethylacetate:methanol:concentrated sulphuric acid were applied to the extract. Deconjugated steroids were then extracted at alkaline pH with tert-butylmethylether. The dried organic extracts were derivatized with MSTFA:NH4I:2-mercaptoethanol to obtain the TMS derivatives, and were subjected to analysis by gas chromatography mass spectrometry (GC/MS). The procedure was validated in boar and horse urine for the following metabolites: norandrosterone, noretiocholanolone, norepiandrosterone, 5@b-estran-3@a, 17@b-diol, 5@a-estran-3@b, 17@b-diol, 5@a-estran-3@b, 17@a-diol, 17@a-nandrolone, 17@bN, 5(10)-estrene-3@a, 17@a-diol, 17@a-estradiol and 17@b-estradiol in the different metabolic fractions. Extraction recoveries were higher than 90% for all analytes in the free fraction, and better than 80% in the glucuronide and sulphate fractions, except for 17@a-estradiol in the glucuronide fraction (74%), and 5@a-estran-3@b, 17@a-diol and 17@bN in the sulphate fraction (close to 70%). Limits of quantitation ranged from 0.05 to 2.1ngmL^-^1 in the free fraction, from 0.3 to 1.7ngmL^-^1 in the glucuronide fraction, and from 0.2 to 2.6ngmL^-^1 in the sulphate fraction. Intra- and inter-assay values for precision, measured as relative standard deviation, and accuracy, measured as relative standard error, were below 15% for most of the analytes and below 25%, for the rest of analytes. The method was applied to the analysis of urine samples collected after administration of 17@bN laureate to boars and horses, and its suitability for the quantitation of the metabolites in the three fractions has been demonstrated.
