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Angelis YS, Sakellariou P, Fragkaki AG, Karnava S, Goula O, Kiousi P, Kioukia-Fougia N, Georgakopoulos C, Loui S, Chlapana F, Kletsas D. New long-standing metabolites of 17α-methyltestosterone are detected in HepG2 cell in vitro metabolic model and in human urine. Drug Test Anal 2024; 16:604-615. [PMID: 37903531 DOI: 10.1002/dta.3589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 08/17/2023] [Accepted: 10/08/2023] [Indexed: 11/01/2023]
Abstract
Novel metabolites of the anabolic androgenic steroid 17α-methyltestosterone have been detected in HepG2 cell in vitro metabolic model and in human urine. Their detection was accomplished through targeted gas chromatography-(tandem) mass spectrometry analysis that has been based on microscale synthesized standards. The related synthesis and the gas chromatography-(tandem) mass spectrometry characterization of the analytical standards are described. All newly presented metabolites have a fully reduced steroid A-ring with either an 17,17-dimethyl-18-nor-Δ13 structure or they have been further oxidized at position 16 of the steroid backbone. Metabolites with 17,17-dimethyl-18-nor-Δ13 structure may be considered as side products of phase II metabolic sulfation of the 17β-hydroxy group of methyltestosterone or its reduced tetrahydro-methyltestosterone metabolites 17α-methyl-5β-androstane-3α,17β-diol and 17α-methyl-5α-androstane-3α,17β-diol that produce the known epimeric 17β-methyl-5β-androstane-3α,17α-diol and 17β-methyl-5α-androstane-3α,17α-diol metabolites. The prospective of these new metabolites to increase detection time windows and improve identification was investigated by applying the World Anti-doping Agency TD2021IDCR criteria. The new metabolites, presented herein, complement the current knowledge on the 17α-methyltestosterone metabolism and in some cases can be used as additional long-term markers in the frame of sport doping drug testing.
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Affiliation(s)
- Yiannis S Angelis
- Doping Control Laboratory of Athens, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Panagiotis Sakellariou
- Doping Control Laboratory of Athens, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Argyro G Fragkaki
- Doping Control Laboratory of Athens, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Sophia Karnava
- Doping Control Laboratory of Athens, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
- Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
| | - Olga Goula
- Doping Control Laboratory of Athens, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Polyxeni Kiousi
- Doping Control Laboratory of Athens, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Nassia Kioukia-Fougia
- Doping Control Laboratory of Athens, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | | | - Stella Loui
- Doping Control Laboratory of Athens, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Fotini Chlapana
- Doping Control Laboratory of Athens, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Dimitris Kletsas
- Doping Control Laboratory of Athens, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
- Laboratory of Cell Proliferation and Ageing, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
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2
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Liu L, Karim Z, Schlörer N, de la Torre X, Botrè F, Zoschke C, Parr MK. Biotransformation of anabolic androgenic steroids in human skin cells. J Steroid Biochem Mol Biol 2024; 237:106444. [PMID: 38092130 DOI: 10.1016/j.jsbmb.2023.106444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/20/2023] [Accepted: 12/07/2023] [Indexed: 02/04/2024]
Abstract
In comparison to well-known drug-metabolizing organs such as the liver, the metabolic capacity of human skin is still not well elucidated despite the widespread use of topical drug application. To gain a comprehensive insight into anabolic steroid metabolism in the skin, six structurally related anabolic androgenic steroids, testosterone, metandienone, methyltestosterone, clostebol, dehydrochloromethyltestosterone, and methylclostebol, were applied to human keratinocytes and fibroblasts derived from the juvenile foreskin. Phase I metabolites obtained from incubation media were analyzed by gas chromatography-mass spectrometry. The 5α-reductase activity was predominant in the metabolic pathways as supported by the detection of 5α-reduced metabolites after incubation of testosterone, methyltestosterone, clostebol, and methylclostebol. Additionally, the stereochemistry structures of fully reduced metabolites (4α,5α-isomers) of clostebol and methylclostebol were newly confirmed in this study by the help of inhouse synthesized reference materials. The results provide insights into the steroid metabolism in human skin cells with respect to the characteristics of the chemical structures.
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Affiliation(s)
- Lingyu Liu
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Straße 2+4, 14195 Berlin, Germany
| | - Ziaul Karim
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Straße 2+4, 14195 Berlin, Germany
| | - Nils Schlörer
- Faculty of Chemistry and Earth Sciences, Friedrich Schiller University Jena, Humboldtstr. 10, 07743 Jena, Germany
| | | | - Francesco Botrè
- Laboratorio Antidoping FMSI, Largo Giulio Onesti 1, 00197 Rome, Italy; REDs - Research and Expertise on Antidoping sciences, ISSUL - Institute de sciences du sport, Université de Lausanne, Synathlon 3224 - Quartier Centre, 1015 Lausanne, Switzerland
| | - Christian Zoschke
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Straße 2+4, 14195 Berlin, Germany; Federal Office of Consumer Protection and Food Safety, Department of Veterinary Drugs, Gerichtstr. 49, 13347 Berlin, Germany
| | - Maria Kristina Parr
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Straße 2+4, 14195 Berlin, Germany.
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3
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Harding C, Viljanto M, Habershon-Butcher J, Taylor P, Scarth J. Equine metabolism of the selective androgen receptor modulator YK-11 in urine and plasma following oral administration. Drug Test Anal 2022; 15:388-407. [PMID: 36519889 DOI: 10.1002/dta.3425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 10/30/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022]
Abstract
YK-11 is a steroidal selective androgen receptor modulator, a compound class prohibited in both equine racing and human sports because of their potentially performance enhancing properties. YK-11 is easily accessible via internet-based supplement vendors making this compound a possible candidate for doping; however, its phases I and II metabolism has not yet been reported in the horse. The purpose of this study was to investigate the in vivo metabolites of YK-11 in urine and plasma following oral administration with three daily doses of 50 mg to two Thoroughbred horses. In vitro incubations with equine liver microsomes/S9 were also performed for use as metabolite reference materials; however, this resulted in the formation of 79 metabolites with little overlap with the in vivo metabolism. In plasma, parent YK-11 and seven phase I metabolites were detected, with five of them also observed in vitro. They were present nonconjugated in plasma, with one metabolite also indicating some glucuronide conjugation. In urine, 11 phase I metabolites were observed, with four of them also observed in vitro and six of them also detected in plasma. Nine metabolites were excreted non-conjugated in urine, with two of them also indicating some sulfate conjugation. Two minor metabolites were detected solely as sulfate conjugates. The most abundant analytes in urine were a mono-O-demethylated breakdown product and di-O-demethylated YK-11. The most abundant analytes in plasma were two isomers of the breakdown product with an additional hydroxylation reaction, which also provided the longest detection time in both matrices.
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Affiliation(s)
- Caitlin Harding
- Sport and Specialised Analytical Services, LGC, Fordham, Cambridgeshire, UK
| | - Marjaana Viljanto
- Sport and Specialised Analytical Services, LGC, Fordham, Cambridgeshire, UK
| | | | - Polly Taylor
- Sport and Specialised Analytical Services, LGC, Fordham, Cambridgeshire, UK
| | - James Scarth
- Sport and Specialised Analytical Services, LGC, Fordham, Cambridgeshire, UK
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4
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Harding C, Viljanto M, Cutler C, Habershon-Butcher J, Biddle S, Scarth J. In vitro and in vivo metabolism of the anabolic-androgenic steroid oxandrolone in the horse. Drug Test Anal 2021; 14:39-55. [PMID: 34378336 DOI: 10.1002/dta.3139] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/29/2021] [Accepted: 07/31/2021] [Indexed: 11/09/2022]
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5
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Savill R, Baues H, Voigt E, Zierau O, Thieme D, Keiler AM. Cell culture as a toolbox to generate phase I metabolites for antidoping screening. Drug Test Anal 2021; 13:1169-1177. [PMID: 33527655 DOI: 10.1002/dta.3009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 01/23/2021] [Accepted: 01/27/2021] [Indexed: 01/31/2023]
Abstract
The knowledge of the biotransformation of compounds prohibited by the World Anti Doping Agency is of high concern as doping analyses are mostly based on the detection of metabolites instead of the parent compounds abused by athletes. While the self-administration of doping-relevant compounds is from an ethical point of view a rather problematic method to investigate metabolism, the usage of cell culture systems allows for studies on biotransformation in vitro. Five cell culture models with different tissue origin (liver, ovary, skin, kidney, and testis) were comparatively incubated with testosterone and epitestosterone as well as with the synthetic testosterone derivatives 17α-methyltestosterone and 4-chlorotestosterone to investigate the impact of synthetic modifications on phase I metabolic pathways. Cell culture supernatants were analyzed by high-performance liquid chromatography-tandem mass spectrometry. All cell lines possessed the default steroid phase I biotransformation reactions. The highest conversion rate was observed in ovarian (BG-1) and liver cells (HepG2). For BG-1 and skin cells (HaCaT), the 5α-reductase products 5α-dihydrotestosterone (for both) and 5α-androstane-3α/β,17β-diol (for BG-1 solely) were found to be prevailing after testosterone incubation. In kidney (COS-1) and HepG2 cells, the 17β-hydroxysteroid dehydrogenase activity was predominant as supported by the observation that the 17α-OH (epitestosterone) and the methyl group (17α-methyltestosterone) impeded the conversion rate in these cell lines. In conclusion, future work should extend the characterization of the BG-1 and HepG2 cells on phase II metabolic pathways to examine whether they are suitable models for the generation of metabolite reference collections comparable to those obtained by human excretion studies.
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Affiliation(s)
- Ryan Savill
- Molecular Cell Physiology and Endocrinology, Institute of Zoology, Technical University Dresden, Dresden, Germany
| | - Helge Baues
- Molecular Cell Physiology and Endocrinology, Institute of Zoology, Technical University Dresden, Dresden, Germany
| | - Emmely Voigt
- Molecular Cell Physiology and Endocrinology, Institute of Zoology, Technical University Dresden, Dresden, Germany
| | - Oliver Zierau
- Molecular Cell Physiology and Endocrinology, Institute of Zoology, Technical University Dresden, Dresden, Germany
| | - Detlef Thieme
- Institute of Doping Analysis and Sports Biochemistry Dresden, Kreischa, Germany
| | - Annekathrin Martina Keiler
- Molecular Cell Physiology and Endocrinology, Institute of Zoology, Technical University Dresden, Dresden, Germany.,Institute of Doping Analysis and Sports Biochemistry Dresden, Kreischa, Germany
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6
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Moreira F, Carmo H, Guedes de Pinho P, Bastos MDL. Doping detection in animals: A review of analytical methodologies published from 1990 to 2019. Drug Test Anal 2021; 13:474-504. [PMID: 33440053 DOI: 10.1002/dta.2999] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 12/10/2020] [Accepted: 01/08/2021] [Indexed: 01/09/2023]
Abstract
Despite the impressive innate physical abilities of horses, camels, greyhounds, or pigeons, doping agents might be administered to these animals to improve their performance. To control these illegal practices, anti-doping analytical methodologies have been developed. This review compiles the analytical methods that have been published for the detection of prohibited substances administered to animals involved in sports over 30 years. Relevant papers meeting the search criteria that discussed analytical methods aiming to detect and/or quantify doping substances in animal biological matrices published from 1990 to 2019 were considered. A total of 317 studies were included, of which 298 were related to horses, demonstrating significant advances toward the development of doping detection methods for equine sports. However, analytical methods for the detection of doping agents in sports involving other species are lacking. Due to enhanced accuracy and specificity, chromatographic analysis coupled to mass spectrometry detection is preferred over immunoassays. Regarding biological matrices, blood and urine remain the first choice, although alternative biological matrices, such as hair and feces, have been considered. With the increasing number and type of drugs used as doping agents, the analytes addressed in the published papers are diverse. It is very important to continue to detect and quantify these drugs, recognizing those that are most frequently used, in order to punish the abusers, protect animals' health, and ensure a healthier and genuine competition.
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Affiliation(s)
- Fernando Moreira
- UCIBIO/REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.,Departamento de Medicina Legal e Ciências Forenses, Faculdade de Medicina, Universidade do Porto, Porto, Portugal.,Área Técnico-Científica de Farmácia, Escola Superior de Saúde, Instituto Politécnico do Porto, Porto, Portugal
| | - Helena Carmo
- UCIBIO/REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Paula Guedes de Pinho
- UCIBIO/REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Maria de Lourdes Bastos
- UCIBIO/REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
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7
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Feeney W, Moorthy AS, Sisco E. Spectral trends in GC-EI-MS data obtained from the SWGDRUG mass spectral library and literature: A resource for the identification of unknown compounds. Forensic Chem 2020; 31:10.1016/j.forc.2022.100459. [PMID: 36578315 PMCID: PMC9793444 DOI: 10.1016/j.forc.2022.100459] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Rapid identification of new or emerging psychoactive substances remains a critical challenge in forensic drug chemistry laboratories. Current analytical protocols are well-designed for confirmation of known substances yet struggle when new compounds are encountered. Many laboratories initially attempt to classify new compounds using gas chromatography-electron ionization-mass spectrometry (GC-EI-MS). Though there is a large body of research focused on the analysis of illicit substances with GC-EI-MS, there is little high-level discussion of mass spectral trends for different classes of drugs. This manuscript compiles literature information and performs simple exploratory analyses on evaluated GC-EI-MS data to investigate mass spectral trends for illicit substance classes. Additionally, this work offers other important aspects: brief discussions of how each class of drugs is used; illustrations of EI mass spectra with proposed structures of commonly observed ions; and summaries of mass spectral trends that can help an analyst classify new illicit compounds.
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Affiliation(s)
- William Feeney
- Corresponding author at: Surface and Trace Chemical Analysis Group, Material Measurement Laboratory, 100 Bureau Drive, Gaithersburg, MD 20899, USA. (W. Feeney)
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8
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Cawley AT, Blakey K, Waller CC, McLeod MD, Boyd S, Heather A, McGrath KC, Handelsman DJ, Willis AC. Detection and metabolic investigations of a novel designer steroid: 3-chloro-17α-methyl-5α-androstan-17β-ol. Drug Test Anal 2015; 8:621-32. [DOI: 10.1002/dta.1832] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 05/11/2015] [Accepted: 05/28/2015] [Indexed: 01/30/2023]
Affiliation(s)
- Adam T. Cawley
- Australian Racing Forensic Laboratory; Racing NSW; Randwick NSW Australia
| | - Karen Blakey
- Forensic and Scientific Services, Health Support Queensland; Department of Health, Queensland Government; Archerfield QLD Australia
| | - Christopher C. Waller
- Research School of Chemistry; Australian National University; Canberra ACT Australia
| | - Malcolm D. McLeod
- Research School of Chemistry; Australian National University; Canberra ACT Australia
| | - Sue Boyd
- Magnetic Resonance Facility, School of Natural Sciences; Griffith University; Nathan QLD Australia
| | - Alison Heather
- Faculty of Science; University of Technology; Sydney NSW Australia
- Currently with the Department of Physiology; University of Otago; Dunedin New Zealand
| | | | | | - Anthony C. Willis
- Research School of Chemistry; Australian National University; Canberra ACT Australia
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9
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Metabolism of anabolic steroids and their relevance to drug detection in horseracing. Bioanalysis 2011; 2:1085-107. [PMID: 21083210 DOI: 10.4155/bio.10.57] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The fight against doping in sport using analytical chemistry is a mature area with a history of approximately 100 years in horseracing. In common with human sport, anabolic/androgenic steroids (AASs) are an important group of potential doping agents. Particular issues with their detection are extensive metabolism including both phase I and phase II. A number of the common AASs are also endogenous to the equine. A further issue is the large number of synthetic steroids produced as pharmaceutical products or as 'designer' drugs intended to avoid detection or for the human supplement market. An understanding of the metabolism of AASs is vital to the development of effective detection methods for equine sport. The aim of this paper is to review current knowledge of the metabolism of appropriate steroids, the current approaches to their detection in equine sport and future trends that may affect equine dope testing.
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10
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Scarth JP, Teale P, Kuuranne T. Drug metabolism in the horse: a review. Drug Test Anal 2010; 3:19-53. [DOI: 10.1002/dta.174] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 08/02/2010] [Accepted: 08/02/2010] [Indexed: 12/13/2022]
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Abstract
This chapter reviews drug and medication control in equestrian sports and addresses the rules of racing, the technological advances that have been made in drug detection and the importance of metabolism studies in the development of effective drug surveillance programmes. Typical approaches to screening and confirmatory analysis are discussed, as are the quality processes that underpin these procedures. The chapter also addresses four specific topics relevant to equestrian sports: substances controlled by threshold values, the approach adopted recently by European racing authorities to control some therapeutic substances, anabolic steroids in the horse and LC-MS analysis in drug testing in animal sports and metabolism studies. The purpose of discussing these specific topics is to emphasise the importance of research and development and collaboration to further global harmonisation and the development and support of international rules.
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Affiliation(s)
- Ed Houghton
- HFL Sport Science, Newmarket Road, Fordham, Cambridgeshire, UK.
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12
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Pozo ÓJ, Van Eenoo P, Deventer K, Lootens L, Van Thuyne W, Parr MK, Schänzer W, Sancho JV, Hernández F, Meuleman P, Leroux-Roels G, Delbeke FT. Detection and Characterization of a New Metabolite of 17α-Methyltestosterone. Drug Metab Dispos 2009; 37:2153-62. [DOI: 10.1124/dmd.109.028373] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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13
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Modern techniques for the determination of anabolic–androgenic steroid doping in the horse. Bioanalysis 2009; 1:785-803. [DOI: 10.4155/bio.09.52] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Control of the use of performance-affecting substances in the horse is critical to the integrity of a wide range of equine sports, with major implications for both animal welfare and revenue streams. One class of medications enjoying particular public notoriety is the anabolic–androgenic steroid group, as highlighted by the recent ‘Big Brown’ affair and Congressional inquiries into the use of steroids in professional sports, including horse racing, in the USA. This review examines the latest developments pertaining to the analytical detection of these substances in equine biological samples and the supporting regulatory environment. Consideration is given to the full variety of sample matrices available, together with modern sample preparative approaches and instrumental techniques. Issues concerning the regulation of endogenous steroids, including thresholds where applicable, are also discussed.
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Galesio M, Rial-Otero R, Capelo-Martínez JL. Comparative study of matrices for their use in the rapid screening of anabolic steroids by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2009; 23:1783-1791. [PMID: 19444857 DOI: 10.1002/rcm.4074] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
New data on sample preparation and matrix selection for the fast screening of androgenic anabolic steroids (AAS) by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) is presented. The rapid screening of 15 steroids included in the World Anti-Doping Agency (WADA) prohibited list using MALDI was evaluated. Nine organic and two inorganic matrices were assessed in order to determine the best matrix for steroid identification in terms of ionisation yield and interference by characteristic matrix ions. The best results were achieved for the organic matrices 2-(4-hydroxyphenylazo)benzoic acid (HABA) and trans-3-indoleacrylic acid (IAA). Good signals for all the steroids studied were obtained for concentrations as low as 0.010 and 0.050 microg/mL on the MALDI sample plate for the HABA and IAA matrices, respectively. For these two matrices, the sensitivity achieved by MALDI is comparable with the sensitivity achieved by gas chromatography/mass spectrometry (GC/MS), which is the conventional technique used for AAS detection. Furthermore, the accuracy and precision obtained with MALDI are very good, since an internal mass calibration is performed with the matrix ions. For the inorganic matrices, laser fluences higher than those used with organic matrices are required to obtain good MALDI signals. When inorganic matrices were used in combination with glycerol as a dispersing agent, an important reduction of the background noise was observed. Urine samples spiked with the study compounds were processed by solid-phase extraction (SPE) and the screening was consistently positive.
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Affiliation(s)
- M Galesio
- REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnología, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
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YAMADA M, ARAMAKI S, HOSOE T, KUROSAWA M, KIJIMA-SUDA I, SAITO K, NAKAZAWA H. Characterization and Quantification of Fluoxymesterone Metabolite in Horse Urine by Gas Chromatography/Mass Spectrometry. ANAL SCI 2008; 24:911-4. [DOI: 10.2116/analsci.24.911] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
| | | | - Tomoo HOSOE
- Faculty of Pharmaceutical Sciences, Hoshi University
| | | | | | - Koichi SAITO
- Faculty of Pharmaceutical Sciences, Hoshi University
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16
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YAMADA M, ARAMAKI S, KUROSAWA M, KIJIMA-SUDA I, SAITO K, NAKAZAWA H. Simultaneous Doping Analysis of Main Urinary Metabolites of Anabolic Steroids in Horse by Ion-trap Gas Chromatography-Tandem Mass Spectrometry. ANAL SCI 2008; 24:1199-204. [DOI: 10.2116/analsci.24.1199] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
| | | | | | | | - Koichi SAITO
- Department of Analytical Chemistry, Hoshi University
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