Screening of testosterone esters in human plasma

Ultraviolet spectra determination and computational analysis of 44 E/Z steroid isomers in dried blood spot

The dried blood spot (DBS) is a novel alternative matrix used in 2022 Beijing Winter Olympics and Paralympics. It is capable of distinguishing anabolic androgenic steroid (AAS) esters without the gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) confirmation. In this study, a method for detection of 22 anabolic steroid esters in DBS based on ultra-high liquid chromatography-mass spectrometry (UPLC-MS) with parallel reaction monitoring (PRM) was developed and validated. Methoxylamine was used as the derivatization reagent to improve the sensibility. Specificity, limit of detection (LOD), linearity, stability, robustness, and carryover were evaluated. Steroid esters are nine testosterone esters, six nandrolone esters, five boldenone esters, methenolone enanthate, and trenbolone acetate. UV spectra were determined by HPLC. And density functional theory (DFT) calculation methods could provide theoretical UV spectra data. Three basis set of B3LYP/6-31G(d), B3LYP/6-31+G(d, p), and WB97XD/6-31+G(d, p) were used for the geometry optimizations and TD-DFT calculation. The average deviation (%RD) of B3LYP/6-31+G(d) for all 44 ester oximes are less than 3.0%. This study for the first time provides a method to tentatively identify the 44 E/Z configurations of steroid oxime products.

Simultaneous detection of testosterone, nandrolone, and boldenone esters in dried blood spots for doping control in sports by liquid chromatography-tandem mass spectrometry

Testosterone, nandrolone, and boldenone, which are listed as doping substances on the World Anti-Doping Agency Prohibited List, are mostly available commercially in esterified forms. Isotope ratio mass spectrometry (IRMS) represents a key tool for identifying these substances, as they are hydrolyzed and discharged in the urine as pseudo-endogenous substances. However, IRMS, which comprises a complicated process, cannot achieve the direct detection of steroid esters in blood samples. These substances can be detected using dried blood spots (DBSs), reducing the impact of esterase hydrolysis. Here, a simultaneous liquid chromatography-tandem mass spectrometry method for detecting 28 steroid (13 testosterone, nine nandrolone, and six boldenone) esters was developed using three DBS types of samples, including a cellulose paper and polymer. The substances were first derivatized with methyloxime to increase their sensitivities (the limits of detection were <0.1-0.4, <0.1-0.9, and <0.1-0.9 ng/mL for the testosterone, nandrolone, and boldenone esters, respectively). Further, the DBS absorbents were verified since the effect of interferences depended on it. Next, a study involving seven participants was conducted to detect intramuscularly administered testosterone enanthate (100 mg). Polymer and cellulose papers were used to collect blood from their upper arms and fingertips, respectively, and testosterone enanthate was identified and detectable at both blood-collection sites for up to 144 and 216 h, respectively. Furthermore, testosterone enanthate was detectable in the DBS samples stored under refrigeration after 6 months, indicating the stable nature of DBS.

Comparison of analytical approaches for the detection of oral testosterone undecanoate administration in men

For antidoping laboratories, the determination of an illicit testosterone (T) administration in urine samples remains a difficult process as it requires the determination of the exogenous origin by carbon isotope ratios (CIRs) of testosterone and its metabolites. As a complement to the urinary analysis, targeting testosterone esters (e.g. testosterone undecanoate [TU]) in serum samples by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) could represent a simpler approach compared with isotope ratio mass spectrometry (IRMS). These two approaches both lead to the direct detection of the administration of exogenous T but with a difference in effort and complexity of the analysis. To compare the detection window obtained with the two strategies, serum and the corresponding urine samples collected from an administration study with oral TU were analysed. Results showed that, at all timepoints where the intact TU was detected in serum, the CIRs of urinary steroids were also not in agreement with an endogenous origin. IRMS analysis required more effort but resulted in slightly longer detection windows than the ester analysis. Finally, this comparison study showed that, in the presence of a suspicious urinary steroid profile, the LC-MS/MS steroid esters analysis in the corresponding serum samples can be very helpful. If steroid esters are not detected, the IRMS analysis can then be conducted on the urine sample afterwards. Overall, the combination of matrices might facilitate the detection of prohibited T administration in sports, especially for athletes with naturally low T/E ratios.

Stability and detectability of testosterone esters in dried blood spots after intramuscular injections

While misuse of testosterone esters is widespread in elite and recreational sports, direct detection of intact testosterone esters in doping control samples is hampered by the rapid hydrolysis by esterases present in the blood. With dried blood spot (DBS) as sample matrix, continued degradation of the esters is avoided due to inactivation of the hydrolase enzymes in dried blood. Here, we have developed the method further for detection of testosterone esters in DBS with focus on robustness and applicability in doping control. To demonstrate the method's feasibility, DBS samples from men receiving two intramuscular injections of Sustanon® 250 (n = 9) or placebo (n = 10) were collected, transported, and stored prior to analysis, to mimic a doping control scenario. The presented nanoLC-HRMS/MS method appeared reliable and suitable for direct detection of four testosterone esters (testosterone decanoate, isocaproate, phenylpropionate, and propionate) after extraction from DBS. Sustanon® was detected in all subjects for at least 5 days, with detection window up to 14 days for three of the esters. Evaluation of analyte stability showed that while storage at room temperature is tolerated well for a few days, testosterone esters are highly stable (>18 months) in DBS when stored in frozen conditions. Collectively, these findings demonstrate the applicability of DBS sampling in doping control for detection of steroid esters. The fast collection and reduced shipment costs of DBS compared with urine and standard blood samples, respectively, will allow more frequent and/or large-scale testing to increase detection and deterrence.

The Roles of Androgens in Humans: Biology, Metabolic Regulation and Health

Androgens are an important and diverse group of steroid hormone molecular species. They play varied functional roles, such as the control of metabolic energy fate and partition, the maintenance of skeletal and body protein and integrity and the development of brain capabilities and behavioral setup (including those factors defining maleness). In addition, androgens are the precursors of estrogens, with which they share an extensive control of the reproductive mechanisms (in both sexes). In this review, the types of androgens, their functions and signaling are tabulated and described, including some less-known functions. The close interrelationship between corticosteroids and androgens is also analyzed, centered in the adrenal cortex, together with the main feedback control systems of the hypothalamic-hypophysis-gonads axis, and its modulation by the metabolic environment, sex, age and health. Testosterone (T) is singled out because of its high synthesis rate and turnover, but also because age-related hypogonadism is a key signal for the biologically planned early obsolescence of men, and the delayed onset of a faster rate of functional losses in women after menopause. The close collaboration of T with estradiol (E2) active in the maintenance of body metabolic systems is also presented Their parallel insufficiency has been directly related to the ravages of senescence and the metabolic syndrome constellation of disorders. The clinical use of T to correct hypoandrogenism helps maintain the functionality of core metabolism, limiting excess fat deposition, sarcopenia and cognoscitive frailty (part of these effects are due to the E2 generated from T). The effectiveness of using lipophilic T esters for T replacement treatments is analyzed in depth, and the main problems derived from their application are discussed.

Androgens, sports, and detection strategies for anabolic drug use

For decades, anabolic androgenic agents have represented the substance class most frequently observed in doping control samples. They comprise synthetic and pseudoendogenous anabolic androgenic steroids and other, mostly non-steroidal compounds with (presumed) positive effects on muscle mass and function. While exogenous substances can easily be detected by gas/liquid chromatography and mass spectrometry, significantly more complex methodologies including the longitudinal monitoring of individual urinary steroid concentrations/ratios and isotope ratio mass spectrometry are required to provide evidence for the exogenous administration of endogenous compounds. This narrative review summarizes the efforts made within the last 5 years to further improve the detection of anabolic agents in doping control samples. Different approaches such as the identification of novel metabolites and biomarkers, the acquisition of complementary mass spectrometric data, and the development of new analytical strategies were employed to increase method sensitivity and retrospectivity while simultaneously reducing method complexity to facilitate a higher and faster sample throughput.

Current Insights into the Steroidal Module of the Athlete Biological Passport

For decades, the class of anabolic androgenic steroids has represented the most frequently detected doping agents in athletes' urine samples. Roughly 50% of all adverse analytical findings per year can be attributed to anabolic androgenic steroids, of which about 2/3 are synthetic exogenous steroids, where a qualitative analytical approach is sufficient for routine doping controls. For the remaining 1/3 of findings, caused by endogenous steroid-derived analytical test results, a more sophisticated quantitative approach is required, as their sheer presence in urine cannot be directly linked to an illicit administration. Here, the determination of urinary concentrations and concentration ratios proved to be a suitable tool to identify abnormal steroid profiles. Due to the large inter-individual variability of both concentrations and ratios, population-based thresholds demonstrated to be of limited practicability, leading to the introduction of the steroidal module of the Athlete Biological Passport. The passport enabled the generation of athlete-specific individual reference ranges for steroid profile parameters. Besides an increase in sensitivity, several other aspects like sample substitution or numerous confounding factors affecting the steroid profile are addressed by the Athlete Biological Passport-based approach. This narrative review provides a comprehensive overview on current prospects, supporting professionals in sports drug testing and steroid physiology.

New approach to derivatisation for oestradiol esters detection in animal blood plasma using negative chemical ionisation GC-MS

In 1996, the EU prohibited the use of substances with anabolic action for food-producing animals (EU Directive 96/22/EC). In cases of illegal use of steroid hormones, these substances are usually applied to the animals in the form of esters. The reliable determination of intact steroid esters in animal tissues or body fluids is an unequivocal proof of illegal treatment of animals with EU prohibited anabolic substances. Previously our laboratory developed a sensitive method for determination of oestradiol benzoate and other steroid esters in blood plasma using LC-MS/MS, validated according to Commission Decision 2002/657/EC. This study describes a GC-MS method which has been developed for five oestradiol esters in blood plasma. The sample preparation procedure consisted of protein precipitation, phospholipids removal and cleaning on an alumina column. Oestradiol esters were derivatised with 2, 3, 4, 5, 6-pentafluorobenzoyl chloride (PFBCl) and pyridine in dichloromethane. The measurement of oestradiol esters was carried out by GC-MS/NCI with Cool On-Column injection. Methane was used as a negative chemical ionisation reagent gas. The method for determination of oestradiol esters in blood plasma has been validated according to Commission Decision 2002/657/EC. Decision limits for all analytes were observed below 0.05 ng mL^-1. The method is robust for bovine and porcine plasma analyses and can be applied both for screening and confirmatory determination in routine residue monitoring.

Liquid chromatography-mass spectrometry behavior of Girard's reagent T derivatives of oxosteroid intact phase II metabolites for doping control purposes

Intact phase II steroid metabolites have poor product ion mass spectra under collision-induced dissociation (CID) conditions. Therefore, we present herein the liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/(MS)) behavior of intact phase II metabolites of oxosteroids after derivatization. Based on the fact that Girard's reagent T (GRT), as derivatization reagent, was both convenient and efficient in terms of the enhancement in the ionization efficiency and the production of diagnostic product ions related to the steroid moiety, the latter was preferably selected between methoxamine and hydroxylamine upon the model compounds of androsterone glucuronide and androsterone sulfate. Sixteen different glucuronides and 29 sulfate conjugated metabolites of anabolic androgenic steroids (AASs), available either as pure reference materials or synthesized/extracted from administration studies, were derivatized with GRT, and their product ion spectra are presented. Product ion spectra include in all cases high number of product ions that in some cases are characteristic for certain structures of the steroid backbone. More specifically, preliminary results have shown major differences in fragmentation pattern for 17α/17β-isomers of the sulfate conjugates, but limited differentiation for 17α/17β-isomers of glucuronide conjugates and for 3α/3β- and 5α/5β-stereoisomers of both sulfate and glucuronide conjugates. Further to the suggestion of the current work, application on mesterolone administration studies confirmed-according to the World Anti-Doping Agency (WADA) TD2015IDCR-the presence of seven intact phase II metabolites, one glucuronide and six sulfates with use of LC-ESI-MS/(MS).

Dried blood spots in doping analysis

A series of dried blood spot (DBS) detection methods for doping agents have been developed in the last two decades. The DBS technique minimizes invasiveness and reduces storage and shipping costs. Recently, the World Anti-Doping Agency announced the use of DBS for the 2022 Beijing Winter Olympic Games and Paralympic Games owing to the advantages of the DBS application in routine doping control. Therefore the further development of detection methods for doping agents in DBS is important and urgent. This review summarizes five aspects of DBS application in doping analysis: sample collection, storage conditions, pretreatment, instrumentation and validation according to the Prohibited List issued by the World Anti-Doping Agency, and proposes some suggestions for future studies of DBS in doping analysis.

Improving the detection of anabolic steroid esters in human serum by LC-MS

The detection of the abuse of pseudo-endogenous steroids in sport is articulated in two different levels: an initial testing procedure, based on the longitudinal evaluation of the urinary androgenic steroid profile by gas-chromatography mass spectrometry (GC-MSⁿ), and a confirmation analysis, based on the differentiation between the endogenous and exogenous origin of the pseudo-endogenous steroids by gas-chromatography coupled to isotopic ratio mass spectrometry (GC/C/IRMS). The abuse of pharmaceutical preparations displaying a carbon isotopic composition values within a range similar to those reported for endogenous urinary steroids makes more difficult the application of GC/C/IRMS technique. To overcome this limitation, the direct detection of an intact synthetic anabolic steroid ester in blood matrices (plasma and/or serum) could supply the unequivocal proof of exogenous administration of pseudo-endogenous steroids. Here we are presenting a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the analysis of 14 testosterone (T) esters and 2 nandrolone (Nand) esters in human serum. Sample pre-treatment consisted of protein precipitation, liquid-liquid extraction and derivatization. The formation of three different derivatives (oxime derivatives, Girard P and Girard T hydrazones) is considered, in order to guarantee an improvement in the detection capability of the assay with respect to underivatized compounds. Once the most suitable derivative was selected, the method was validated, according to the World Anti-Doping Agency (WADA) criteria, in terms of specificity, linearity, limit of detection (LOD), extraction recovery, matrix effect (ion suppression/enhancement), carry over and autosampler stability. The formation of Girard P hydrazones of T and Nand esters provides the best results compared to the underivatized compounds, oxime and Girard T derivatives, respectively. The presented analytical method is specific for all considered compounds and linear in the range of concentrations investigated (0.25-10 ng/mL). The LODs are between 0.03 and 0.30 ng/mL, the extraction recovery higher than 70 % for all esters and no remarkable matrix effect, expressed in terms of ion enhancement and ion suppression, was observed. Finally, the developed and validate method was applied in the analysis of serum samples collected after the administration of a single dose (40 mg, 1 capsule) of testosterone undecanoate (Andriol ®) demonstrating its applicability.

Analysis of testosterone fatty acid esters in the digestive gland of mussels by liquid chromatography-high resolution mass spectrometry

Several studies have indicated that up to 70% of the total steroids detected in molluscs are in the esterified form and that pollutants, by modifying the esterification of steroids with fatty acids, might act as endocrine disrupters. However, despite the strong physiological significance of this process, there is almost no information on which fatty acids form the steroid esters and how this process is modulated. This study (a) investigates the formation of fatty acid esters of testosterone in digestive gland microsomal fractions of the mussel Mytilus galloprovincialis incubated with either palmitoly-CoA or CoA and ATP, and (b) assesses whether the endocrine disruptor tributyltin (TBT) interferes with the esterification of testosterone. Analysis of testosterone esters was performed by liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). When microsomal fractions were incubated with testosterone and palmitoly-CoA, the formation of testosterone palmitate was detected. However, when microsomes were incubated with CoA and ATP, and no exogenous activated fatty acid was added, the synthesis of 16:0, 16:1, 20:5 and 22:6 testosterone esters was observed. The presence of 100µM TBT in the incubation mixture did not significantly alter the esterification of testosterone. These results evidence the conjugation of testosterone with the most abundant fatty acids in the digestive gland microsomal fraction of mussels.

Development of the fast, simple and fully validated high performance liquid chromatographic method with diode array detector for quantification of testosterone esters in an oil-based injectable dosage form

Counterfeit steroids are available on the black market, ultimately to consumers who believe they are buying a legitimate pharmaceutical item from the labeled company. In many cases, counterfeit steroids can contain lower doses or some products can be overdosed. This can unwittingly expose users to a significant health risks. The mixture of testosterone propionate, phenylpropionate, isocaproate and decanoate in an oil-based injectable dosage form belongs to the one of the most misused illicit drugs by a variety of athletes. This study developed a new, fast, simple and reliable HPLC method combined with a simple sample preparation step to determine testosterone propionate, phenylpropionate, isocaproate and decanoate in an oil-based injectable dosage form without the use of sophisticated and expensive instrumentation. The developed analytical procedure provides high throughput of samples where LC analysis takes only 6min and sample preparation of oil matrix in one step takes approximately 10min with precision ranging from 1.03 to 3.38% (RSD), and accuracy (relative error %) within ±2.01%. This method was found to be precise, linear, accurate, sensitive, selective and robust for routine application in screening of commercial pharmaceutical products based on content of mentioned testosterone esters in their oil-based injectable dosage form for counterfeit drugs. This method was successfully applied to the analysis of nine samples of commercial testosterone mixtures purchased from various sources and will be further used as an effective screening method for determination of previously mentioned testosterone esters in samples confiscated by Institute of Forensic Science (Slovakia) during the illegal trade.

Current status and recent advantages in derivatization procedures in human doping control

Derivatization is one of the most important steps during sample preparation in doping control analysis. Its main purpose is the enhancement of chromatographic separation and mass spectrometric detection of analytes in the full range of laboratory doping control activities. Its application is shown to broaden the detectable range of compounds, even in LC–MS analysis, where derivatization is not a prerequisite. The impact of derivatization initiates from the stage of the metabolic studies of doping agents up to the discovery of doping markers, by inclusion of the screening and confirmation procedures of prohibited substances in athlete's urine samples. Derivatization renders an unlimited number of opportunities to advanced analyte detection.

High throughput quantification of prohibited substances in plasma using thin film solid phase microextraction

Simple, fast and efficient sample preparation approaches that allow high-throughput isolation of various compounds from complex matrices are highly desired in bioanalysis. Particularly sought are methods that can, without sacrificing time, easily remove matrix interferences capable of inducing ionization suppression/enhancement, or causing detrimental effects in instrumental performance. In this work, an automated high-throughput sample preparation method using thin film solid phase microextraction (SPME) for the analysis of multiple prohibited substances in plasma is proposed. A biocompatible SPME extraction phase made of hydrophilic-lipophilic balance particles immobilized with polyacrylonitrile (PAN) demonstrated satisfactory extraction capabilities for 25 compounds of a wide range of polarities (logP from -2 to 6.8). Due to the well-known biocompatible characteristics of PAN-based SPME coatings, minimum sample handling was required. Experimental conditions for pre-conditioning, extraction, wash and desorption were carefully optimized for the proposed method. By taking full advantage of the 96 thin film handling capability of the automated system, a preparation time of approximately 1.5min per sample can be achieved. Satisfactory results in terms of absolute matrix effects were found for the majority of the studied analytes, given that 24 out of 25 compounds exhibited values in the range of 100 and 120%. The method was validated in terms of linearity (R(2)>0.99), inter and intra-day accuracy (85-130%) and precision (<20%) and limits of quantitation (0.25-10ngmL(-1) for most compounds).