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1.
J Anal Toxicol ; 46(9): e307-e313, 2023 Jan 24.
Article in English | MEDLINE | ID: mdl-36516229

ABSTRACT

A 29-year-old man with no previous medical history was found dead at home. Anabolic products (tablets and oily solutions) and syringes were found at the scene. The man was known to train regularly at a fitness club and to use anabolic drugs. Following an unremarkable autopsy with normal histology, toxicological analyses were requested by the local prosecutor to provide further information. Blood, head hair (5 cm, black), body hair (axillary and leg) and toe and finger nail clippings were submitted to liquid and gas chromatography coupled to tandem mass spectrometry (LC and GC-MS-MS) methods to test for anabolic steroids. Blood tested positive for testosterone (4 ng/mL), boldenone (26 ng/mL), stanozolol (3 ng/mL) and trenbolone (<1 ng/mL). Segmental head hair tests (2 × 2.5 cm) revealed a repeated consumption of testosterone (65-72 pg/mg), testosterone propionate (930-691 pg/mg), testosterone isocaproate (79 pg/mg to <5 pg/mg), nandrolone decanoate (202-64 pg/mg), boldenone (16 pg/mg), stanozolol (575-670 pg/mg), trenbolone (4 pg/mg-not detected), drostanolone (112-30 pg/mg), drostanolone enanthate (26-5 pg/mg) and drostanolone propionate (15-4 pg/mg). In addition to the substances identified in head hair, testosterone decanoate, testosterone cypionate and nandrolone were identified in both body hair and nails. The experts concluded that the manner of death can be listed as toxic due to massive repetitive use of anabolic steroids during the previous months. For anabolic agents, blood does not seem to be the best matrix to document a fatal intoxication. Indeed, these products are toxics when abused long term and are known to cause cardiac, hepatic and renal diseases. When compared to blood, hair and nails have a much larger window of detection. Therefore, keratinous matrices seem to be the best approach to test for anabolic steroids when a sudden death is observed in the context of possible abuse of steroids.


Subject(s)
Anabolic Agents , Humans , Adult , Anabolic Agents/analysis , Stanozolol/analysis , Keratins/analysis , Trenbolone Acetate/analysis , Gas Chromatography-Mass Spectrometry/methods , Testosterone , Testosterone Congeners/analysis , Hair/chemistry
2.
Drug Test Anal ; 13(11-12): 1921-1928, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34505743

ABSTRACT

A fundamental challenge in preventive doping research is the study of metabolic pathways of substances banned in sport. However, the pharmacological predictions obtained by conventional in vitro or in vivo animal studies are occasionally of limited transferability to humans according to an inability of in vitro models to mimic higher order system physiology or due to various species-specific differences using animal models. A more recently established technology for simulating human physiology is the "organ-on-a-chip" principle. In a multichannel microfluidic cell culture chip, 3-dimensional tissue spheroids, which can constitute artificial and interconnected microscale organs, imitate principles of the human physiology. The objective of this study was to determine if the technology is suitable to adequately predict metabolic profiles of prohibited substances in sport. As model compounds, the frequently misused anabolic steroids, stanozolol and dehydrochloromethyltestosterone (DHCMT) were subjected to human liver spheroids in microfluidic cell culture chips. The metabolite patterns produced and circulating in the chip media were then assessed by LC-HRMS/(MS) at different time points of up to 14 days of incubation at 37°C. The overall profile of observed glucurono-conjugated stanozolol metabolites excellently matched the commonly found urinary pattern of metabolites, including 3'OH-stanozolol-glucuronide and stanozolol-N-glucuronides. Similarly, but to a lower extent, the DHCMT metabolic profile was in agreement with phase-I and phase-II biotransformation products regularly seen in postadministration urine specimens. In conclusion, this pilot study indicates that the "organ-on-a-chip" technology provides a high degree of conformity with traditional human oral administration studies, providing a promising approach for metabolic profiling in sports drug testing.


Subject(s)
Lab-On-A-Chip Devices , Stanozolol/analysis , Substance Abuse Detection/methods , Testosterone/analogs & derivatives , Chromatography, Liquid/methods , Doping in Sports/prevention & control , Feasibility Studies , Humans , Liver/metabolism , Pilot Projects , Spheroids, Cellular/metabolism , Stanozolol/metabolism , Tandem Mass Spectrometry/methods , Testosterone/analysis , Testosterone/metabolism
3.
Drug Test Anal ; 13(9): 1668-1677, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34089570

ABSTRACT

The exogenous anabolic-androgenic steroid (AAS) stanozolol stays one of the most detected substances in professional sports. Its detection is a fundamental part of doping analysis, and the analysis of this steroid has been intensively investigated for a long time. This contribution to the detection of stanozolol doping describes for the first time the unambiguous proof for the existence of 17-epistanozolol-1'N-glucuronide and 17-epistanozolol-2'N-glucuronide in stanozolol-positive human urine samples due to the access to high-quality reference standards. Examination of excretion study samples shows large detection windows for the phase-II metabolites stanozolol-1'N-glucuronide and 17-epistanozolol-1'N-glucuronide up to 12 days and respectively up to almost 28 days. In addition, we present appropriate validation parameters for the analysis of these metabolites using a fully automatic method online solid-phase extraction (SPE) method already published before. Limits of identification (LOIs) as low as 100 pg/ml and other validation parameters like accuracy, precision, sensitivity, robustness, and linearity are given.


Subject(s)
Anabolic Agents/analysis , Doping in Sports/prevention & control , Stanozolol/analysis , Substance Abuse Detection/methods , Anabolic Agents/metabolism , Anabolic Agents/urine , Female , Glucuronides/analysis , Glucuronides/urine , Humans , Limit of Detection , Male , Solid Phase Extraction/methods , Stanozolol/metabolism , Stanozolol/urine , Time Factors
4.
Molecules ; 25(9)2020 Apr 26.
Article in English | MEDLINE | ID: mdl-32357494

ABSTRACT

The use of doping in sports is a global problem that affects athletes around the world. Among the different methods developed to detect doping agents in biological samples, there are antibody-based methods that need an appropriate hapten design. Steroids with a hydroxyl group can be converted to the corresponding hemisuccinates. A novel approach to the synthesis of 17ß-O-hemisuccinate of the common doping agent stanozolol is described here. Acylation of stanozolol with methyl 4-chloro-4-oxobutyrate/4-dimethylaminopyridine, followed by mild alkaline hydrolysis with methanolic sodium hydroxide at room temperature, gave the simultaneous protection and deprotection of pyrazole-nitrogen atoms. The proposed new synthetic method allows the desired hemisuccinate derivative to be obtained in only two steps, and with a good total yield starting from stanozolol.


Subject(s)
Doping in Sports/prevention & control , Stanozolol/analysis , Steroids/analysis , Substance Abuse Detection/methods , Succinates/chemical synthesis , Acylation , Anabolic Agents/analysis , Androgens/analysis , Chromatography, Thin Layer , Humans , Magnetic Resonance Spectroscopy , Stanozolol/chemistry , Succinates/analysis , Succinates/chemistry
5.
J Anal Toxicol ; 44(8): 834-839, 2020 Dec 12.
Article in English | MEDLINE | ID: mdl-32128595

ABSTRACT

An athlete challenged the result from an in-competition doping test which returned with an adverse analytical finding for stanozolol, claiming it was due to supplement contamination. Her lawyer asked the laboratory to analyze several hair specimens simultaneously collected from five different anatomical regions, head, arm, leg, pubis and armpit, to document the pattern of drug exposure. A specific UPLC-MS-MS method was developed. After decontamination with dichloromethane, stanozolol was extracted from hair in the presence of stanozolol-d3 used as internal standard, under alkaline conditions, with diethyl ether. Linearity was observed for concentrations ranging from 5 pg/mg to 10 ng/mg. The method has been validated according to linearity, precision and matrix effect. Concentrations of stanozolol in head hair, pubic hair, arm hair, leg hair and axillary hair were 73, 454, 238, 244 and 7,100 pg/mg, respectively. The concentration of stanozolol in head hair is in accordance with data published in the literature. When comparing the concentrations, body hair concentrations were higher than the concentration found in head hair. These results are consistent with a better incorporation rate of stanozolol in body hair when compared to head hair. The simultaneous positive concentrations in different hair types confirm the adverse analytical finding in urine of the top athlete, as the measured concentrations do not support the theory of contamination. For the first time, an anabolic agent was simultaneously tested in hair collected from five different anatomical regions from the same subject, with a large distribution of concentrations, due to anatomical variations, and these findings will help interpretation in further doping cases when documented with hair.


Subject(s)
Anabolic Agents/analysis , Hair/chemistry , Stanozolol/analysis , Chromatography, High Pressure Liquid , Chromatography, Liquid , Doping in Sports , Female , Humans , Tandem Mass Spectrometry
6.
Forensic Sci Int ; 303: 109925, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31499423

ABSTRACT

A 34-year old male was found breathless and panting at home by his girlfriend three hours after a gym workout. Minutes later, he collapsed and died. Autopsy, histological and chemical analyses were conducted. The examination of the heart showed left ventricular hypertrophy, while the right coronary artery showed only a small vascular lumen (3 mm in diameter), due to its anatomical structure. In femoral blood concentrations of approx. 1 µg/L clenbuterol, approx. 56 µg/L stanozolol and approx. 8 µg/L metandienone, with trenbolone (

Subject(s)
Anabolic Agents/adverse effects , Clenbuterol/adverse effects , Doping in Sports , Methandrostenolone/adverse effects , Stanozolol/adverse effects , Adult , Anabolic Agents/analysis , Androstanols/urine , Clenbuterol/analysis , Clomiphene/urine , Coronary Vessels/pathology , Fatal Outcome , Heart Failure/chemically induced , Humans , Hypertrophy, Left Ventricular/pathology , Male , Methandrostenolone/analysis , Stanozolol/analysis , Testosterone/analogs & derivatives , Testosterone/urine , Trenbolone Acetate/blood , Trenbolone Acetate/urine
7.
Biosensors (Basel) ; 8(1)2017 Dec 26.
Article in English | MEDLINE | ID: mdl-29278383

ABSTRACT

We have studied the Fourier Transform Infrared (FT-IR) and the Fourier transform Raman (FT-Raman) spectra of stanozolol and oxandrolone, and we have performed quantum chemical calculations based on the density functional theory (DFT) with a B3LYP/6-31G (d, p) level of theory. The FT-IR and FT-Raman spectra were collected in a solid phase. The consistency between the calculated and experimental FT-IR and FT-Raman data indicates that the B3LYP/6-31G (d, p) can generate reliable geometry and related properties of the title compounds. Selected experimental bands were assigned and characterized on the basis of the scaled theoretical wavenumbers by their total energy distribution. The good agreement between the experimental and theoretical spectra allowed positive assignment of the observed vibrational absorption bands. Finally, the calculation results were applied to simulate the Raman and IR spectra of the title compounds, which show agreement with the observed spectra.


Subject(s)
Anabolic Agents/analysis , Oxandrolone/analysis , Quantum Theory , Stanozolol/analysis , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis, Raman
8.
Article in English | MEDLINE | ID: mdl-27842983

ABSTRACT

Stanozolol is one of the most commonly abused anabolic androgenic steroids (AAS) by athletes and usually detected by its parent drug and major metabolites. However, its metabolic pathway is complex, varied and individually different, it is important to characterize its overall metabolic profiles and discover new and long-term metabolites for the aims of expanding detection windows. High performance liquid chromatography coupled with triple quadrupole mass spectrometer (HPLC-MS/MS) was used to analyze the human urine after oral administration of stanozolol. Multiple reaction monitoring (MRM), one of the scan modes of triple quadrupole mass spectrometer showing extremely high sensitivity was well used to develop a strategy for metabolic profiles characterization and long-term metabolites detection based on typical precursor to product ion transitions of parent drug and its major metabolites. Utilizing the characteristic fragment ions of stanozolol and its major metabolites as the product ions, and speculating unknown precursor ions based on the possible phase I and phase II metabolic reactions in human body, the metabolite profiles of stanozolol could be comprehensively discovered, especially for those unknown and low concentration metabolites in human urine. Then these metabolites were further well structure identified by targeted high resolution MS/MS scan of quadrupole-time of flight mass spectrometry (Q-TOF). Applying this strategy, 27 phase I and 21 phase II metabolites of stanozolol were identified, in which 13 phase I and 14 phase II metabolites have not been reported previously. The 9 out of 48 metabolites could be detected over 15days post drug administration. This strategy could be employed effectively to characterize AAS metabolic profiles and discover unknown and long-term metabolites in sports drug testing.


Subject(s)
Anabolic Agents/urine , Chromatography, High Pressure Liquid/methods , Stanozolol/urine , Substance Abuse Detection/methods , Tandem Mass Spectrometry/methods , Adult , Anabolic Agents/analysis , Anabolic Agents/metabolism , Doping in Sports , Female , Humans , Limit of Detection , Male , Metabolic Networks and Pathways , Stanozolol/analysis , Stanozolol/metabolism , Young Adult
9.
Article in English | MEDLINE | ID: mdl-25719897

ABSTRACT

A sensitive method for the identification and quantification of anabolic steroids and clenbuterol at trace levels in dietary supplements by liquid chromatography-high-resolution mass spectrometry (LC-HRMS) in atmospheric pressure ionisation (APCI) mode using a single-stage Orbitrap analyser operating at a resolution power of 100 000 full width at half maximum (FWHM) was developed and validated. A total of 1 g of dietary supplement was added with testosterone-d3 as internal standard, dissolved in methanol, evaporated to dryness, diluted in sodium hydroxide solution and extracted with a mixture of pentane/ethyl ether 9:1. The extract was directly injected into the LC-HRMS system. The method was fully validated. Limits of detection (LODs) obtained for anabolic androgenic steroids (AASs) varied from 1 to 25 ng g(-1) and the limit of quantitation (LOQ) was 50 ng g(-1) for all analytes. The calibration was linear for all compounds in the range from the LOQ to 2000 ng g(-1), with correlation coefficients always higher than 0.99. Accuracy (intended as %E) and repeatability (%CV) were always lower than 15%. Good values of matrix effect and recovery were achieved. The ease of the sample preparation together with a fast run time of only 16 min permitted rapid identification of the analytes. The method was applied to the analysis of 30 dietary supplements in order to check for the presence of anabolic agents not labelled as being present in these supplements. Many AASs were often detected in the same sample: indeed, androstenedione was detected in nine supplements, 5-androsten-3ß-ol-17-one (DHEA) in 12, methandienone in three, stanozolol in one, testosterone in seven and testosterone esters in four of them. A retrospective analysis of suspected compounds not included at the beginning of the method development was also possible by means of the full acquisition spectra obtained with the HRMS technique.


Subject(s)
Anabolic Agents/analysis , Chromatography, Liquid , Dietary Supplements/analysis , Mass Spectrometry , Dehydroepiandrosterone/analysis , Limit of Detection , Methandrostenolone/analysis , Reproducibility of Results , Sensitivity and Specificity , Stanozolol/analysis , Testosterone/analogs & derivatives , Testosterone/analysis , Testosterone Propionate/analogs & derivatives , Testosterone Propionate/analysis
11.
Methods Mol Biol ; 811: 207-21, 2012.
Article in English | MEDLINE | ID: mdl-22042682

ABSTRACT

This chapter presents as a proof of concept the development of a nanosensor based on the localized surface plasmon resonance for the analysis of biomolecules. The method presented take advantage of the plasmon generated in the surrounding of gold nanoparticles (i.e., 100 nm) for the specific interaction between antigen and antibody. The procedure for the optimization of an assay for the determination of biomolecules consisted mainly of four steps. First, the immobilization of gold nanoparticles over the glass surface using the appropriate ratio, concentration and time-contact of amino-sylilating agent, and nonreactive sylilating agent. Next, the suitable concentration of coating antigen in order to obtain the maximum signal LSPR. Following this step, the interaction between antigen and antibody (specific antibody) is evaluated by measuring the signal LSPR. Finally, a calibration curve was obtained for the detection of a small organic molecule such as stanozolol using this nanobiosensor. As a proof of concept, the use of a model is performed that in this case is for the detection of an anabolic androgenic steroid, such as stanozolol which is banned for the European Commission (EC) as a growth promoter and for the World Anti-Doping Agency (WADA) as a doping agent. The nanosensor developed demonstrates its feasibility for screening purposes due to the limit of detection achieved (0.7 µg/L) is under the MRPL required for both organizations (10 µg/L). A protocol such as that presented here may be generally applied for the analysis of other pollutant such as pesticides or antibiotics, or for biomedical applications for the analysis of biomarkers using the LSPR principle using gold nanoparticles (i.e., 30-120 nm).


Subject(s)
Antigen-Antibody Reactions , Biosensing Techniques/methods , Gold/chemistry , Nanoparticles/chemistry , Nanotechnology/methods , Surface Plasmon Resonance/methods , Biomarkers/analysis , Biosensing Techniques/instrumentation , Environmental Pollutants/analysis , Stanozolol/analysis
12.
Steroids ; 75(10): 710-4, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20435054

ABSTRACT

New highly sensitive, specific, reliable, reproducible and robust LC-MS/MS methods were developed to detect the anabolic steroids, nandrolone and stanozolol, in human hair for the first time. Hair samples from 180 participants (108 males, 72 females, 62% athletes) were screened using ELISA which revealed 16 athletes as positive for stanozolol and 3 for nandrolone. Positive samples were confirmed on LC-MS/MS in selective reaction monitoring (SRM) mode. The assays for stanozolol and nandrolone showed good linearity in the range 1-400pg/mg and 5-400pg/mg, respectively. The methods were validated for LLOD, interday precision, intraday precision, specificity, extraction recovery and accuracy. The assays were capable of detecting 0.5pg stanozolol and 3.0pg nandrolone per mg of hair, when approximately 20mg of hair were processed. Analysis using LC-MS/MS confirmed 11 athletes' positive for stanozolol (5.0pg/mg to 86.3pg/mg) and 1 for nandrolone (14.0pg/mg) thus avoiding false results from ELISA screening. The results obtained demonstrate the application of these hair analysis methods to detect both steroids at low concentrations, hence reducing the amount of hair required significantly. The new methods complement urinalysis or blood testing and facilitate improved doping testing regimes. Hair analysis benefits from non-invasiveness, negligible risk of infection and facile sample storage and collection, whilst reducing risks of tampering and cross-contamination. Owing to the wide detection window, this approach may also offer an alternative approach for out-of-competition testing.


Subject(s)
Anabolic Agents/analysis , Doping in Sports/prevention & control , Hair/chemistry , Chromatography, Liquid , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Nandrolone/analysis , Reproducibility of Results , Stanozolol/analysis , Tandem Mass Spectrometry
13.
ACS Nano ; 4(3): 1473-80, 2010 Mar 23.
Article in English | MEDLINE | ID: mdl-20146439

ABSTRACT

A proof of concept of the electronic detection of two anabolic steroids, stanozolol (Stz) and methylboldenone (MB), was carried out using two specific antibodies and arrays of carbon nanotube field-effect transistors (CNTFETs). Antibodies specific for Stz and MB were prepared and immobilized on the carbon nanotubes (CNTs) using two different approaches: direct noncovalent bonding of antibodies to the devices and bonding the antibodies covalently to a polymer previously attached to the CNTFETs. The results indicated that CNTFETs bonded to specific antibodies covalently or noncovalently are able to detect the presence of steroids. Statistically significant changes in the threshold voltage and drain current were registered in the transistors, allowing the steroids to be recognized. On the other hand, it was determined that the specific antibodies do not detect other steroids other than Stz and MB, such as nandrolone (ND) because, in this case, statistically significant changes in the transistors were not detected. The polymer prevents the aggregation of antibodies on the electrodes and decreases the transistor hysteresis. Nevertheless, it is not able to avoid the nonspecific adsorption of streptavidin, meaning that nonspecific adsorption on CNTs remains a problem and that this methodology is only useful for purified samples. Regarding the detection mechanism, in addition to charge transfer, Schottky barrier, SB, modification, and scattering potential reported by other authors, an electron/hole trapping mechanism leading to hysteresis modification has been determined. The presence of polymer seems to hinder the modulation of the electrode-CNT contact.


Subject(s)
Anabolic Agents/analysis , Biosensing Techniques/methods , Electrons , Immunoassay/methods , Nanotubes, Carbon/chemistry , Steroids/analysis , Transistors, Electronic , Adsorption , Anabolic Agents/immunology , Animals , Antibodies, Immobilized/chemistry , Antibodies, Immobilized/immunology , Antibody Specificity , Biosensing Techniques/instrumentation , Electrodes , Immunoassay/instrumentation , Stanozolol/analysis , Stanozolol/immunology , Steroids/immunology , Streptavidin/analysis , Streptavidin/chemistry , Streptavidin/immunology , Substrate Specificity , Testosterone/analogs & derivatives , Testosterone/analysis , Testosterone/chemistry , Testosterone/immunology
14.
Steroids ; 75(1): 57-69, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19854209

ABSTRACT

In this study, the use of equine liver/lung microsomes and S9 tissue fractions were used to study the metabolism of the androgenic/anabolic steroid stanozolol as an example of the potential of in vitro technologies in sports drug surveillance. In vitro incubates were analysed qualitatively alongside urine samples originating from in vivo stanozolol administrations using LC-MS on a high-resolution accurate mass Thermo Orbitrap Discovery instrument, by LC-MS/MS on an Applied Biosystems Sciex 5500 Q Trap and by GC-MS/MS on an Agilent 7000A. Using high-resolution accurate mass full scan analysis on the Orbitrap, equine liver microsome and S9 in vitro fractions were found to generate all the major phase-1 metabolites observed following in vivo administrations. Additionally, analysis of the liver microsomal incubates using a shallower HPLC gradient combined with various MS/MS functions on the 5500 Q trap allowed the identification of a number of phase 1 metabolites previously unreported in the equine or any other species. Comparison between liver and lung S9 metabolism showed that the liver was the major site of metabolic activity in the equine. Furthermore, using chemical enzyme inhibitors that are known to be selective for particular isoforms in other species suggested that an enzyme related to CYP2C8 may be responsible the production of 16-hydroxy-stanozolol metabolites in the equine. In summary, the in vitro and in vivo phase 1 metabolism results reported herein compare well and demonstrate the potential of in vitro studies to compliment the existing in vivo paradigm and to benefit animal welfare through a reduction and refinement of animal experimentation.


Subject(s)
Doping in Sports , Stanozolol/analysis , Stanozolol/urine , Substance Abuse Detection/methods , Anabolic Agents/administration & dosage , Anabolic Agents/chemistry , Anabolic Agents/metabolism , Androgens/administration & dosage , Androgens/analysis , Androgens/metabolism , Animals , Aryl Hydrocarbon Hydroxylases/antagonists & inhibitors , Aryl Hydrocarbon Hydroxylases/metabolism , Chromatography, Gas , Chromatography, High Pressure Liquid , Horses , Hydroxytestosterones/chemistry , Hydroxytestosterones/metabolism , Ketoconazole/pharmacology , Microsomes, Liver/drug effects , Microsomes, Liver/metabolism , Molecular Structure , Quercetin/pharmacology , Reproducibility of Results , Spectrometry, Mass, Electrospray Ionization , Stanozolol/administration & dosage
15.
Se Pu ; 26(4): 469-72, 2008 Jul.
Article in Chinese | MEDLINE | ID: mdl-18959244

ABSTRACT

A rapid and sensitive method was developed for the identification and quantification of stanozolol in hair. After alkaline hydrolysis, the hair sample (10 mg) was extracted with pentane, and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI) and multiple reaction monitoring (MRM). The limit of quantification was found to be 25 pg/mg. After shaving hair on the back of the cavies, they were received after a single intraperitoneal dosing of stanozolol of 60 mg/kg. The hair segments were shaved once every two days for two weeks. The concentration of stanozolol in segmented hair reached the highest at the 10th day. The features of the method are of small sample size, specific, sensitive and suitable for the determinationof stanozolol in hair.


Subject(s)
Chromatography, Liquid/methods , Hair/chemistry , Stanozolol/analysis , Tandem Mass Spectrometry/methods , Animals , Doping in Sports , Guinea Pigs , Limit of Detection , Linear Models , Reproducibility of Results , Time Factors
16.
Anal Bioanal Chem ; 391(5): 1813-20, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18373230

ABSTRACT

This work reports the systematic preparation of biosensors through the use of functionalized glass substrates, noble metal gold colloid, and measurement by localized surface plasmon resonance (LSPR). Glass substrate was modified through chemical silanization, and the density of gold colloid was carefully controlled by optimizing the conditions of silanization through the use of mixed silanes and selective mixing procedures. At this point, samples were exposed to bioreagents and changes in the shallow dielectric constant around the particles were observed by dark-field spectroscopy. Biological binding of high affinity systems (biotin/streptavidin and antigen/antibody) was subsequently investigated by optimizing coating layers, receptor concentration profiling, and finally quantitative determination of the analyte of interest, which in this case was a small organic molecule-the widely used, synthetic anabolic steroid called stanozolol. For this system, high specificity was achieved (>97%) through extensive nonspecific binding tests, with a sensitivity measurable to a level below the minimum required performance level (MRPL) as determined by standard chromatographic methods. Analytical best-fit parameters of Hillslope and regression coefficient are also commented on for the final LSPR biosensor. The LSPR biosensor showed good reproducibility (<5% RSD) and allowed for rapid preparation of calibration curves and determination of the analyte (measurement time of each sample ca. 2 min). As an alternative method for quantitative steroidal analysis, this approach significantly simplifies the detection setup while reducing the cost of analysis. In addition the system maintains comparable sensitivity to standard surface plasmon resonance methods and offers great potential for miniaturization and development of multiplexed devices.


Subject(s)
Biosensing Techniques/methods , Gold Colloid/chemistry , Nanoparticles/chemistry , Stanozolol/analysis , Surface Plasmon Resonance/methods , Antibodies/immunology , Antigens/immunology , Biotin/chemistry , Reproducibility of Results , Sensitivity and Specificity , Silanes/chemistry , Streptavidin/chemistry , Surface Properties
17.
Sud Med Ekspert ; 50(1): 27-31, 2007.
Article in Russian | MEDLINE | ID: mdl-17338339

ABSTRACT

3'-Hydroxystanosolol detection in biological fluids at pg levels by gas chromatography/tandem mass spectrometry is described. Gas chromatography/high resolution mass spectrometry results can be confirmed with gas chromatography/tandem mass-spectrometry.


Subject(s)
Body Fluids/chemistry , Forensic Toxicology/methods , Gas Chromatography-Mass Spectrometry/methods , Stanozolol/analogs & derivatives , Tandem Mass Spectrometry/methods , Humans , Sensitivity and Specificity , Stanozolol/analysis
18.
Anal Chim Acta ; 586(1-2): 122-9, 2007 Mar 14.
Article in English | MEDLINE | ID: mdl-17386703

ABSTRACT

An emerging trend is recognised in hormone and veterinary drug residue analysis from liquid chromatography tandem mass spectrometry (LC/MS/MS) based screening and confirmation towards accurate mass alternatives such as LC coupled with time-of-flight (TOF), Fourier transform ion cyclotron resonance (FTICR) or Fourier transform orbitrap (FT Orbitrap) MS. In this study, mass resolution and accuracy are discussed for LC/MS screening and confirmation of targeted analytes and for the identification of unknowns using the anabolic steroid stanozolol and the designer beta-agonist "Clenbuterol-R" as model substances. It is shown theoretically and experimentally that mass accuracy criteria without proper mass resolution criteria yield false compliant (false negative) results, both in MS screening and MS/MS confirmation of stanozolol. On the other hand, previous medium resolution accurate mass TOFMS/MS data of the designer beta-agonist were fully confirmed by high resolution FT Orbitrap MS(n) experiments. A discussion is initiated through a proposal for additional criteria for the use of accurate mass LC/MS technologies, to be implemented in Commission Decision 2002/657/EC.


Subject(s)
Chemistry Techniques, Analytical/methods , Chromatography, Liquid/methods , Drug Residues/analysis , Ions , Mass Spectrometry/methods , Steroids/analysis , Animals , Clenbuterol/chemistry , Cyclotrons , Fourier Analysis , Models, Chemical , Reproducibility of Results , Sensitivity and Specificity , Spectrometry, Mass, Electrospray Ionization/methods , Stanozolol/analysis
19.
Biomed Chromatogr ; 21(2): 164-8, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17146762

ABSTRACT

In numerous studies it has been demonstrated that several nutritional supplements contain prohormones not declared on the label. In the current study two products (effervescent tablets) containing high amounts of the 17-methylated anabolic androgenic steroids metandienone (product 1: 16.8 mg/tablet) and stanozolol (product 2: 14.5 mg/tablet) were identified. Additionally in both products norandrostenedione was detected, in product 2 with minor amounts of several other steroids. The substances identified can cause enormous health risks. In addition, the use of the analyzed tablets can lead to positive doping results for metabolites of the respective steroids in sports. This study again shows the insufficient surveillance of the production and trade of dietary supplements. Consumers should be aware of the enormous health and doping risks connected with the use of such products. For GC-MS identification of the analytes the trimethylsilyl derivatives of the steroids and the mixed N-t-butyldimethylsilyl,O-trimethylsilyl derivatives were used. The quantitation of metandienone, norandrostenedione, and stanozolol was performed using HPLC-DAD.


Subject(s)
Anabolic Agents/analysis , Androgens/analysis , Dietary Supplements/analysis , Methandrostenolone/analysis , Stanozolol/analysis , Chromatography, High Pressure Liquid/methods , Dietary Supplements/standards , Doping in Sports/prevention & control , Gas Chromatography-Mass Spectrometry/methods , Trimethylsilyl Compounds/analysis , Trimethylsilyl Compounds/chemistry
20.
Biosens Bioelectron ; 21(7): 1345-9, 2006 Jan 15.
Article in English | MEDLINE | ID: mdl-15935632

ABSTRACT

Within this communication, consistent evidence of a quantitative biosensing principle for steroidal residue analysis is presented. Our approach uses a simple method for the quantitative determination of an anabolic agent called stanozolol (Sz). Sz (Mw 328) is widely used in sports, horse racing and as a growth promoter in animals for human consumption. Through the use of localised surface plasmons (LSPs), sustained by three-dimensional noble metal nanostructures, we have developed a highly specific, label-less immunosensor for the detection of this small organic molecule to low levels (nM range). A main practical advantage over conventional flat extended film surface plasmon resonance (SPR) systems is the simplicity of the optical configuration, since there is no need for cumbersome total internal reflection illumination, thus making integration easier. In addition, the active area of the LSP-based sensor is smaller, decreasing the minimum detectable number of molecules involved in the binding event. Assay times are short and the set-up is comprised of relatively cheap instrumentation. Detection levels found here are comparable with SPR, even at this early stage of development and with further modifications, we envisage sensing down to pM (10(-12)) levels.


Subject(s)
Biosensing Techniques/instrumentation , Doping in Sports/prevention & control , Immunoassay/instrumentation , Microchemistry/instrumentation , Stanozolol/analysis , Substance Abuse Detection/instrumentation , Surface Plasmon Resonance/instrumentation , Biosensing Techniques/methods , Equipment Design , Equipment Failure Analysis , Immunoassay/methods , Microchemistry/methods , Stanozolol/immunology , Substance Abuse Detection/methods , Surface Plasmon Resonance/methods
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