Skip to Content
Merck
  • Detection and characterization of betamethasone metabolites in human urine by LC-MS/MS.

Detection and characterization of betamethasone metabolites in human urine by LC-MS/MS.

Drug testing and analysis (2014-12-30)
Xavier Matabosch, Oscar J Pozo, Núria Monfort, Clara Pérez-Mañá, Magí Farré, Jordi Segura, Rosa Ventura
ABSTRACT

Glucocorticosteroids are prohibited in sports when administered by systemic routes and allowed using other administrations for therapeutic reasons. Therefore, markers to distinguish between routes of administration through the analysis of urine samples are needed in anti-doping control. As a first step to achieve that goal, the metabolism of betamethasone (BET) was investigated in the present work. Urine samples obtained after BET intramuscular injection were hydrolyzed with β-glucuronidase and subjected to liquid-liquid extraction with ethyl acetate in alkaline conditions. The extracts were analyzed by liquid chromatography coupled to tandem mass spectrometry. Common open screening methods for fluorine containing corticosteroids (precursor ion scan method of m/z 121, 147, 171, and neutral loss (NL) scan methods of 20 and 38 Da in positive ionization, and 46 and 76 Da in negative ionization) were applied to detect BET metabolites. Moreover, an NL method was applied to detect A-ring reduced metabolites of BET, which are ionized as [M+NH4 ](+) (NL of 55, 73, and 91 Da, corresponding to the consecutive losses of NH3 , HF and one, two and three water molecules, respectively). BET and 24 metabolites were detected. Six metabolites were identified by comparison with standards, and for ten, feasible structures were proposed based on mass spectrometric data. Eleven of the characterized metabolites had not been previously reported. Metabolites resulting from 11-oxidation, 6-hydroxylation, C20 or 4-ene-3-one reduction and combination of some of them were detected. Moreover one metabolite resulting from cleavage of the side chain with subsequent oxidation of carbon at C17 was also detected.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Acetonitrile solution, contains 10.0% acetone, 0.05% formic acid, 40.0% 2-propanol
Pricing and availability is not currently available.
Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (w/v) ammonium formate, 5 % (v/v) water, 0.1 % (v/v) formic acid, suitable for HPLC
Pricing and availability is not currently available.
Sigma-Aldrich
Sodium phosphate dibasic solution, BioUltra, 0.5 M in H2O
Pricing and availability is not currently available.
Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (v/v) trifluoroacetic acid
Pricing and availability is not currently available.
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) trifluoroacetic acid, suitable for HPLC
Pricing and availability is not currently available.
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) formic acid, suitable for HPLC
Pricing and availability is not currently available.
Sigma-Aldrich
Methanol, HPLC Plus, ≥99.9%, poly-coated bottles
Pricing and availability is not currently available.
Sigma-Aldrich
VenPure® SF, powder
Pricing and availability is not currently available.
Sigma-Aldrich
Ammonium chloride, for molecular biology, suitable for cell culture, ≥99.5%
Pricing and availability is not currently available.
Sigma-Aldrich
Betamethasone 21-phosphate disodium, ≥97%
Pricing and availability is not currently available.
Sigma-Aldrich
Methanol, anhydrous, 99.8%
Pricing and availability is not currently available.
Sigma-Aldrich
Ammonium formate, ≥99.995% trace metals basis
Pricing and availability is not currently available.
Sigma-Aldrich
Ammonium chloride, 99.99% trace metals basis
Pricing and availability is not currently available.
Sigma-Aldrich
Sodium borohydride solution, 2.0 M in triethylene glycol dimethyl ether
Pricing and availability is not currently available.
Sigma-Aldrich
Ammonium chloride, 99.998% trace metals basis
Pricing and availability is not currently available.
Sigma-Aldrich
Sodium borohydride solution, ~12 wt. % in 14 M NaOH
Pricing and availability is not currently available.
Sigma-Aldrich
Ammonium chloride, BioUltra, for molecular biology, ≥99.5% (AT)
Pricing and availability is not currently available.
Sigma-Aldrich
Ethyl acetate
Pricing and availability is not currently available.
Sigma-Aldrich
Ammonium formate solution, BioUltra, 10 M in H2O
Pricing and availability is not currently available.
Sigma-Aldrich
Methanol-12C, 99.95 atom % 12C
Pricing and availability is not currently available.
Supelco
Ammonium formate solution, 10 mM in H2O, suitable for HPLC
Pricing and availability is not currently available.
Sigma-Aldrich
Ammonium-14N chloride, 99.99 atom % 14N, 15N-depleted, 99% (CP)
Pricing and availability is not currently available.
Sigma-Aldrich
Sodium borohydride, purum p.a., ≥96% (gas-volumetric)
Pricing and availability is not currently available.
Sigma-Aldrich
Sodium borohydride, ReagentPlus®, 99%
Pricing and availability is not currently available.
Sigma-Aldrich
Ethyl acetate, natural, ≥99%, FCC, FG
Pricing and availability is not currently available.
Sigma-Aldrich
Sodium phosphate dibasic, 99.95% trace metals basis
Pricing and availability is not currently available.
Sigma-Aldrich
Sodium phosphate dibasic, BioUltra, for molecular biology, ≥99.5% (T)
Pricing and availability is not currently available.
Sigma-Aldrich
Acetonitrile, anhydrous, 99.8%
Pricing and availability is not currently available.
Sigma-Aldrich
Ethyl acetate, ReagentPlus®, ≥99.8%
Pricing and availability is not currently available.
Sigma-Aldrich
Acetonitrile, ≥99.5%, ACS reagent
Pricing and availability is not currently available.