Untargeted metabolomics in doping control: detection of new markers of testosterone misuse by ultrahigh performance liquid chromatography coupled to high-resolution mass spectrometry

A Review of Recent Progress in Drug Doping and Gene Doping Control Analysis

The illicit utilization of performance-enhancing substances, commonly referred to as doping, not only infringes upon the principles of fair competition within athletic pursuits but also poses significant health hazards to athletes. Doping control analysis has emerged as a conventional approach to ensuring equity and integrity in sports. Over the past few decades, extensive advancements have been made in doping control analysis methods, catering to the escalating need for qualitative and quantitative analysis of numerous banned substances exhibiting diverse chemical and biological characteristics. Progress in science, technology, and instrumentation has facilitated the proliferation of varied techniques for detecting doping. In this comprehensive review, we present a succinct overview of recent research developments within the last ten years pertaining to these doping detection methodologies. We undertake a comparative analysis, evaluating the merits and limitations of each technique, and offer insights into the prospective future advancements in doping detection methods. It is noteworthy that the continual design and synthesis of novel synthetic doping agents have compelled researchers to constantly refine and innovate doping detection methods in order to address the ever-expanding range of covertly employed doping agents. Overall, we remain in a passive position for doping detection and are always on the road to doping control.

Future opportunities for the Athlete Biological Passport

The Athlete Biological Passport (ABP) was introduced to complement the direct anti-doping approach by indirectly outlining the possible use of prohibited substances or methods in sports. The ABP proved its effectiveness, at least through a deterrent effect, even though the matrices used for longitudinal monitoring (urine and blood) are subject to many intrinsic (e.g., genetic) and extrinsic (e.g., environmental conditions) confounding factors. In that context, new and more specific biomarkers are currently under development to enhance both the sensitivity and the specificity of the ABP. Multiple strategies are presently being explored to improve this longitudinal monitoring, with the development of the current modules, the investigation of new strategies, or the screening of new types of doping. Nevertheless, due to the variability induced by indirect biomarkers, the consideration of confounding factors should continuously support this research. Beyond tremendous advances in analytical sensitivity, machine learning-based approaches seem inevitable to facilitate an expert interpretation of numerous biological profiles and promote anti-doping efforts. This perspective article highlights the current innovations of the Athlete Biological Passport that seem the most promising. Through different research axes, this short manuscript provides an opportunity to bring together approaches that are more widely exploited (e.g., omics strategies) and others in the early stages of investigation (e.g., artificial intelligence) seeking to develop the ABP.

Metabolomics in clinical and forensic toxicology, sports anti-doping and veterinary residues

Metabolomics is a multidisciplinary field providing workflows for complementary approaches to conventional analytical determinations. It allows for the study of metabolically related groups of compounds or even the study of novel pathways within the biological system. The procedural stages of metabolomics; experimental design, sample preparation, analytical determinations, data processing and statistical analysis, compound identification and validation strategies are explored in this review. The selected approach will depend on the type of study being conducted. Experimental design influences the whole metabolomics workflow and thus needs to be properly assessed to ensure sufficient sample size, minimal introduced and biological variation and appropriate statistical power. Sample preparation needs to be simple, yet potentially global in order to detect as many compounds as possible. Analytical determinations need to be optimised either for the list of targeted compounds or a universal approach. Data processing and statistical analysis approaches vary widely and need to be better harmonised for review and interpretation. This includes validation strategies that are currently deficient in many presented workflows. Common compound identification approaches have been explored in this review. Metabolomics applications are discussed for clinical and forensic toxicology, human and equine sports anti-doping and veterinary residues.

Use of ion mobility-high resolution mass spectrometry in metabolomics studies to provide near MS/MS quality data in a single injection

The use of ion mobility separations (IMSs) in metabolomics approaches has started to be deeply explored in the last years. In this work, the use of liquid chromatography (LC) coupled to IMS-quadrupole time-of-flight mass spectrometry (QTOF MS) has been evaluated in a metabolomics experiments using single injection of the samples. IMS has allowed obtaining cleaner fragmentation spectra, of nearly tandem MS quality, in data-independent acquisition mode. This is much useful in this research area as a second injection, generally applied in LC-QTOF MS workflows to obtain tandem mass spectra, is not necessary, saving time and evading possible compound degradation. As a case study, the smoke produced after combustion of herbal blends used to spray synthetic cannabinoids has been selected as study matrix. The smoke components were trapped in carbon cartridges, desorbed and analyzed by LC-IMS-QTOF MS using different separation mechanisms (reversed phase and HILIC) and acquiring in both positive and negative mode to widen the chemical domain. Partial Least Squares-Discriminant Analysis highlighted several compounds, and ratio between N-Isopropyl-3-(isoquinolinyl)-2-propen-1-amine and quinoline allowed differentiating between tobacco and herbal products. These two compounds were tentatively identified using the cleaner fragmentation spectra from a single injection in the IMS-QTOF MS, with additional confidence obtained by retention time (Rt) and collisional cross section (CCS) prediction using artificial neural networks. Data from this work show that LC-IMS-QTOF is an efficient technique in untargeted metabolomics, avoiding re-injection of the samples for elucidation purposes. In addition, the prediction models for Rt and CCS resulted of help in the elucidation process of potential biomarkers.

Identification of metabolomic changes in horse plasma after racing by liquid chromatography-high resolution mass spectrometry as a strategy for doping testing

Recently, the illegal use of novel technologies, such as gene and cell therapies, has become a great concern for the horseracing industry. As a potential way to control this, metabolomics approaches that comprehensively analyze metabolites in biological samples have been gaining attention. However, it may be difficult to identify metabolic biomarkers for doping because physiological conditions generally differ between resting and exercise states in horses. To understand the metabolic differences in horse plasma between the resting state at training centres and the sample collection stage after racing for doping test (SAD), we took plasma samples from these two stages (n=30 for each stage) and compared the metabolites present in these samples by liquid chromatography-high resolution mass spectrometry. This analysis identified 5,010 peaks, of which 1,256 peaks (approximately 25%) were annotated using KEGG analysis. Principal component analysis showed that the resting state and SAD groups had entirely different metabolite compositions. In particular, the levels of inosine, xanthosine, uric acid, and allantoin, which are induced by extensive exercise, were significantly increased in the SAD group. In addition, many metabolites not affected by extensive exercise were also identified. These results will contribute to the discovery of biomarkers for detecting doping substances that cannot be detected by conventional methods.

Steroidomics for highlighting novel serum biomarkers of testosterone doping

Aim: Quantification of testosterone (T) and 5α-dihydrotestosterone serum concentrations proved to be an efficient alternative to urinary steroid profiling for the detection of T doping. In this context, additional serum markers could be discovered by exploratory untargeted steroidomics studies. Results: Endogenous steroid metabolites were monitored by ultra high-performance liquid chromatography coupled to high-resolution mass spectrometry in serum samples collected during a T administration clinical trial. A three-step workflow for accurate review of annotation was used and multifactorial data analysis allowed highlighting promising serum biomarkers. Longitudinal monitoring of selected compounds was performed to assess T abuse detection capabilities. Conclusion: Application of serum steroidomics showed high potential for biomarker discovery of T doping, suggesting longitudinal monitoring of steroid hormones in serum as a significant improvement in detection of endogenous steroids abuse.

Tracking main environmental factors masking a minor steroidal doping effect using metabolomic analysis of horse urine by liquid chromatography-high-resolution mass spectrometry

There is an urgent need to implement holistic and untargeted doping control protocols with improved discriminatory power, compared to conventional methods that only target doping agents. Metabolomics, which aims to characterize all metabolites present in biological matrices, could fulfill this need. In this context, the aim of this study was to evaluate the impact of environmental factors on the ability to obtain a metabolic signature of stanozolol administration in horse doping situation. Urine samples from 16 horses breeded in two different places were collected over a one-year period, before, during and seven months after the administration of stanozolol, a horse doping agent. Metabolomic analysis was performed using ultra-high pressure reverse phase liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (MS). Results showed a major impact of the nutritional regimen, drug administration (for de-worming purpose) and breeding place on the metabolite profiles of horse urines, which hampered the detection of metabolic perturbations induced by stanozolol administration. After having used MS/MS experiments to characterize some MS features related to these environmental factors, we showed that highlighting and then removing the features impacted by these confounding factors before performing supervised multivariate statistical analyses could address this issue. In conclusion, adequate consideration should be given to environmental and physiological factors; otherwise, they can emerge as confounding factors and conceal doping administration.

Potential of ion mobility-mass spectrometry for both targeted and non-targeted analysis of phase II steroid metabolites in urine

In recent years, the commercialization of hybrid ion mobility-mass spectrometers and their integration in traditional LC-MS workflows provide new opportunities to extend the current boundaries of targeted and non-targeted analyses. When coupled to LC-MS, ion mobility spectrometry (IMS) provides a novel characterization parameter, the so-called averaged collision cross section (CCS, Ω), as well as improves method selectivity and sensitivity by the separation of isobaric and isomeric molecules and the isolation of the analytes of interest from background noise. In this work, we have explored the potential and advantages of this technology for carrying out the determination of phase II steroid metabolites (i.e. androgen and estrogen conjugates, including glucuronide and sulfate compounds; n = 25) in urine samples. These molecules have been selected based on their relevance in the fields of chemical food safety and doping control, as well as in metabolomics studies. The influence of urine matrix on the CCS of steroid metabolites was evaluated in order to give more confidence to current CCS databases and support its use as complementary information to retention time (Rt) and mass spectra for compound identification. Samples were only diluted 10-fold with aqueous formic acid (0.1%, v/v) prior analysis. Only an almost insignificant effect of adult bovine urine matrix on the CCS of certain steroid metabolites was observed in comparison with calve urine matrix, which is a less complex sample. In addition, high accuracy was achieved for CCS measurements carried out over four months (ΔCCS < 1.3% for 99.8% of CCS measurements; n = 1806). Interestingly, it has been observed that signal-to-noise (S/N) ratio could be improved at least 2 or 7-fold when IMS is combined with LC-MS. In addition to the separation of isomeric steroid pairs (i.e. etiocholanolone glucuronide and epiandrosterone glucuronide, as well as 19-noretiocholanolone glucuronide and 19-norandrosterone glucuronide), steroid-based ions were also separated in the IMS dimension from co-eluting matrix compounds that presented similar mass-to-charge ratio (m/z). Finally, based on CCS measurements and as a proof of concept, 17α-boldenone glucuronide has been identified as one of the main metabolites resulted from boldione administration to calves.

Novel strategies for clinical investigation and biomarker discovery: a guide to applied metabolomics

Metabolomics is an emerging technology that is increasing both in basic science and in human applications, providing a physiological snapshot. It has been highlighted as one of the most wide ranging and reliable tools for the investigation of physiological status, the discovery of new biomarkers and the analysis of metabolic pathways. Metabolomics uses innovative mass spectrometry (MS) allied to chromatography or nuclear magnetic resonance (NMR). The recent advances in bioinformatics, databases and statistics, have provided a unique perception of metabolites interaction and the dynamics of metabolic pathways at a system level. In this context, several studies have applied metabolomics in physiology- and disease-related works. The application of metabolomics includes, physiological and metabolic evaluation/monitoring, individual response to different exercise, nutritional interventions, pathological processes, responses to pharmacological interventions, biomarker discovery and monitoring for distinct aspects, such as: physiological capacity, fatigue/recovery and aging among other applications. For metabolomic analyses, despite huge improvements in the field, several complex methodological steps must be taken into consideration. In this regard, the present article aims to summarize the novel aspects of metabolomics and provide a guide for metabolomics for professionals related to physiologist and medical applications.

Untargeted metabolomics profiles delineate metabolic alterations in mouse plasma during lung carcinoma development using UPLC-QTOF/MS in MSE mode

In this work, an untargeted metabolomic method based on ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) in MSE (E represents collision energy) mode was exploited to determine the dynamic metabolic alterations in the plasma of male C57BL/6 mice during the onset and development of lung carcinoma. Plasma samples were collected from control and model mice (male C57BL/6 mice experimentally inoculated with the Lewis lung carcinoma cells) at 7 and 14 days post-inoculation (DPI). As a result, 15 dysregulated metabolites, including cholesterol sulphate, tiglylcarnitine, 1-palmitoylglycerophosphoinositol, 2-stearoylglycerophosphoinositol, stearoylcarnitine, PC(20:2(11Z,14Z)/16:0), PC(22:4(7Z,10Z,13Z,16Z)/14:0), PC(22:5(7Z,10Z,13Z,16Z,19Z)/14:0), PC(22:6(4Z,7Z,10Z,13Z,16Z,19Z)/16:0), 12,20-Dioxo-leukotriene B4, sphingosine 1-phosphate(d19:1-P), sphingomyelin(d18:0/16:1(9Z)), lysoPC(16:0), lysoPC(18:0) and lysoPC(20:4(5Z,8Z,11Z,14Z)), were identified in the plasma of model mice with xenografts at both 7 and 14 DPI. All the altered metabolites associated with the onset and development of lung carcinoma were involved in the metabolism of glycerophospholipid, fatty acid, sphingolipid and arachidonic acid. The feasible utility of these endogenous biomarkers as potential diagnostic indicators was validated through receiver operating characteristic curve analysis. Collectively, these findings provide a systematic view of metabolic changes linked to the onset and development of lung carcinoma.

What about the herb? A new metabolomics approach for synthetic cannabinoid drug testing

Synthetic cannabinoids (SCs) are consumed as legal alternative to cannabis and often allow passing drug-screening tests. Their rapid transience on the drug scene, combined with their mostly unknown metabolic profiles, creates a scenario with constantly moving analytical targets, making their monitoring and identification challenging. The development of fast screening strategies for SCs, not directly focused on their chemical structure, as an alternative to the commonly applied target acquisition methods, would be highly appreciated in forensic and public health laboratories. An innovative untargeted metabolomics approach, focused on herbal components commonly used for 'spice' products, was applied. Saliva samples of healthy volunteers were collected at pre-dose and after smoking herbal components and analysed by high-resolution mass spectrometry. The data obtained, combined with appropriate statistical analysis, allowed to highlight and elucidate two markers (scopoletin and N,N-bis(2-hydroxyethyl)dodecylamine), which ratio permitted to differentiate herbal smokers from non-smokers. The proposed strategy will allow discriminating potential positives, on the basis of the analysis of two markers identified in the herbal blends. This work is presented as a step forward in SC drug testing, promoting a smart first-line screening approach, which will allow reducing the number of samples to be further investigated by more sophisticated HRMS methods. Graphical abstract The development of an alternative, generic screening methods of synthetic cannabinoids, not directly based on the chemical structure, in order to provide fast response on its potential consumption.

Evaluation of markers out of the steroid profile for the screening of testosterone misuse. Part II: Intramuscular administration

In the fight against doping, the introduction of alternative markers to the steroid profile can be considered as an effective approach to improve the screening capabilities for the detection of testosterone (T) misuse. The aim of this study was to evaluate the potential of several T metabolites (cysteinyl conjugated and glucuronoconjugated resistant to enzymatic hydrolysis) to detect both the transdermal and the intramuscular administration of T. In Part I of the study, we studied the potential of these metabolites for the detection of T transdermal administration. Results revealed that resistant glucuronides can be a suitable complement to the current steroid profile. In this, Part II, dedicated to the intramuscular administration, we studied the potential of cysteinyl conjugated, resistant glucuronoconjugated and 1-cyclopentenoylglycine (1-CPG) for the detection of a single intramuscular injection of T cypionate. Possible differences in the excretion profile of all markers were explored between individuals with low basal (n=6) and medium basal (n=6) values of the testosterone/epitestosterone ratio (T/E). The results showed that all tested markers presented low intra-individual stability in basal conditions. Despite this, all glucuronoconjugated markers and 1-CPG, but not the cysteinyl conjugated markers, provided detection windows that were similar or longer than those obtained by markers currently included in the steroid profile. Based on the results obtained from the 2 parts of this study and from previously reported data, the potential applicability and the limitations of including these markers in the steroid profile are discussed.

High-Resolution, Accurate-Mass (HRAM) Mass Spectrometry Urine Steroid Profiling in the Diagnosis of Adrenal Disorders

BACKGROUND

Steroid profiling is a promising diagnostic tool with adrenal tumors, Cushing syndrome (CS), and disorders of steroidogenesis. Our objective was to develop a multiple-steroid assay using liquid-chromatography, high-resolution, accurate-mass mass spectrometry (HRAM LC-MS) and to validate the assay in patients with various adrenal disorders.

METHODS

We collected 24-h urine samples from 114 controls and 71 patients with adrenal diseases. An HRAM LC-MS method was validated for quantitative analysis of 26 steroid metabolites in hydrolyzed urine samples. Differences in steroid excretion between patients were analyzed based on Z-score deviation from control reference intervals.

RESULTS

Limits of quantification were 20 ng/mL. Dilution linearity ranged from 80% to 120% with means of 93% to 110% for all but 2 analytes. Intraassay and interassay imprecision ranged from 3% to 18% for all but 1 analyte. Control women had lower excretion of androgen and glucocorticoid precursors/metabolites than men (P &lt; 0.001), but no difference in mineralocorticoids was seen (P = 0.06). Androgens decreased with age in both sexes (P &lt; 0.001). Compared with patients with adrenocortical adenoma (ACA), patients with adrenocortical carcinoma (ACC) had 11 steroids with increased Z scores, especially tetrahydro-11-deoxycortisol (14 vs 0.5, P &lt; 0.001), pregnanetriol (7.5 vs −0.4, P = 0.001), and 5-pregnenetriol (5.4 vs −0.4, P = 0.01). Steroid profiling also demonstrated metabolite abnormalities consistent with enzymatic defects in congenital adrenal hyperplasia and differences in pituitary vs adrenal CS.

CONCLUSIONS

Our HRAM LC-MS assay successfully quantifies 26 steroids in urine. The statistically significant differences in steroid production of ACC vs ACA, adrenal vs pituitary CS, and in congenital adrenal hyperplasia should allow for improved diagnosis of patients with these diseases.

Metabolomics: A Primer

Metabolomics generates a profile of small molecules that are derived from cellular metabolism and can directly reflect the outcome of complex networks of biochemical reactions, thus providing insights into multiple aspects of cellular physiology. Technological advances have enabled rapid and increasingly expansive data acquisition with samples as small as single cells; however, substantial challenges in the field remain. In this primer we provide an overview of metabolomics, especially mass spectrometry (MS)-based metabolomics, which uses liquid chromatography (LC) for separation, and discuss its utilities and limitations. We identify and discuss several areas at the frontier of metabolomics. Our goal is to give the reader a sense of what might be accomplished when conducting a metabolomics experiment, now and in the near future.

Non-targeted LC-MS based metabolomics analysis of the urinary steroidal profile

The urinary steroidal fraction has been extensively explored as non-invasive alternative to monitor pathological conditions as well as to unveil the illicit intake of pseudo-endogenous anabolic steroids in sport. However, the majority of previous approaches involved the a priori selection of potentially relevant target analytes. Here we describe the non-targeted analysis of the urinary steroidal profiles. The workflow includes minimal sample pretreatment and normalization according to the specific gravity of urine, a 20 min reverse phase ultra-performance liquid chromatographic separation hyphenated to electrospray time-of-flight mass spectrometry. As initial validation, we analyzed a set of quality control urines spiked with glucurono- and sulfo-conjugated steroids at physiological ranges. We then applied the method for the analysis of samples collected after single transdermal administration of testosterone in hypogonadal men. The method allowed profiling of approximately three thousand metabolic features, including steroids of clinical and forensic relevance. It successfully identified metabolic pathways mostly responsible for groups clustering even in the context of high inter-individual variability and allowed the detection of currently unknown metabolic features correlating with testosterone administration. These outcomes set the stage for future studies aimed at implementing currently monitored urinary steroidal markers both in clinical and forensic analysis.

Constant Ion Loss Method for the Untargeted Detection of Bis-sulfate Metabolites

The untargeted detection of phase II metabolites is a key issue for the study of drug metabolism in biological systems. Sensitive and selective mass spectrometric (MS) techniques coupled to ultrahigh performance liquid chromatographic (UHPLC) systems are the most effective for this purpose. In this study, we evaluate different MS approaches with a triple quadrupole instrument for the untargeted detection of bis-sulfate metabolites. Bis-sulfates of 23 steroid metabolites were synthesized and their MS behavior was comprehensively studied. Bis-sulfates ionized preferentially as the dianion ([M - 2H]^2-) with a small contribution of the monoanion ([M - H]^-). Product ion spectra generated from the [M - 2H]^2- precursor ions were dominated by the loss of HSO₄^- to generate two product ions, that is, the ion at m/z 97 (HSO₄^-) and the ion corresponding to the remaining monosulfate fragment. Other product ions were found to be specific for some structures. As an example, the loss of [CH₃ + SO₃]^- was found to be important for several compounds with unsaturation adjacent to the sulfate. On the basis of the common behavior of the bis-sulfate metabolites two alternatives were evaluated for the untargeted detection of bis-sulfate metabolites (i) a precursor ion scan method using the ion at m/z 97 and (ii) a constant ion loss (CIL) method using the loss of HSO₄^-. Both methods allowed for the untargeted detection of the model compounds. Eight steroid bis-sulfates were synthesized in high purity in order to quantitatively evaluate the developed strategies. Lower limits of detection (2-20 ng/mL) were obtained using the CIL method. Additionally, the CIL method was found to be more specific in the detection of urinary bis-sulfates. The applicability of the CIL approach was demonstrated by determining progestogens altered during pregnancy and by detecting the bis-sulfate metabolites of tibolone.

Evaluation of two glucuronides resistant to enzymatic hydrolysis as markers of testosterone oral administration

Testosterone (T) has traditionally been the most commonly reported doping agent by doping control laboratories. The screening of T misuse is performed by the quantification of six endogenous androgenic steroids and the ratio T/E included in the Athlete Biological Passport (ABP). The inclusion of additional metabolites can improve the screening capabilities of ABP. In this study, the potential of 3α-glucuronide-6β-hydroxyandrosterone (6OH-Andros3G) and 3α-glucuronide-6β-hydroxyetiocholanolone (6OH-Etio3G) as markers of T oral administration was evaluated. These glucuronides have been shown to be resistant to enzymatic hydrolysis and their quantification by means of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was reported as the only way to obtain feasible results. Urine samples were collected from five volunteers before and after the oral administration of 40mg of T undecanoate and were analyzed by a LC-MS/MS method recently developed. Concentration of 6OH-Andros3G and 6OH-Etio3G compounds and those of the glucuronides of T (TG), epitestosterone (EG), androsterone and etiocholanolone were established and different concentration ratios were calculated. The detection windows (DWs) for the T administration obtained by each selected ratio were compared to the one of TG/EG. The results showed that four out of the nine tested markers presented DWs much larger for all volunteers than those obtained by the World Anti-Doping Agency established T/E marker or other alternative markers. The 6OH-Andros3G/EG, 6OH-Etio3G/EG, 6OH-Andros3G/TG and 6OH-Etio3G/TG markers were able to identify the T abuse up to 96h after the administration, extending our detection capability for the misuse up to 84h more than the classic marker. The importance of these markers was also highlighted by their prolonged capacity to detect the T misuse in the case of one volunteer whose TG/EG barely exceeded his individual threshold. As a consequence, the four markers presented in this study seem to have an exceptional potential as biomarkers of T oral administration.

Current LC-MS methods and procedures applied to the identification of new steroid metabolites

The study of the metabolism of steroids has a long history; from the first characterizations of the major metabolites of steroidal hormones in the pre-chromatographic era, to the latest discoveries of new forms of excretions. The introduction of mass spectrometers coupled to gas chromatography at the end of the 1960's represented a major breakthrough for the elucidation of new metabolites. In the last two decades, this technique is being complemented by the use of liquid chromatography-mass spectrometry (LC-MS). In addition of becoming fundamental in clinical steroid determinations due to its excellent specificity, throughput and sensitivity, LC-MS has emerged as an exceptional tool for the discovery of new steroid metabolites. The aim of the present review is to provide an overview of the current LC-MS procedures used in the quest of novel metabolic products of steroidal hormones and exogenous steroids. Several aspects regarding LC separations are first outlined, followed by a description of the key processes that take place in the mass spectrometric analysis, i.e. the ionization of the steroids in the source and the fragmentation of the selected precursor ions in the collision cell. The different analyzers and approaches employed together with representative examples of each of them are described. Special emphasis is placed on triple quadrupole analyzers (LC-MS/MS), since they are the most commonly employed. Examples on the use of precursor ion scan, neutral loss scan and theoretical selected reaction monitoring strategies are also explained.

Applications of Fourier Transform Ion Cyclotron Resonance (FT-ICR) and Orbitrap Based High Resolution Mass Spectrometry in Metabolomics and Lipidomics

Metabolomics, along with other "omics" approaches, is rapidly becoming one of the major approaches aimed at understanding the organization and dynamics of metabolic networks. Mass spectrometry is often a technique of choice for metabolomics studies due to its high sensitivity, reproducibility and wide dynamic range. High resolution mass spectrometry (HRMS) is a widely practiced technique in analytical and bioanalytical sciences. It offers exceptionally high resolution and the highest degree of structural confirmation. Many metabolomics studies have been conducted using HRMS over the past decade. In this review, we will explore the latest developments in Fourier transform mass spectrometry (FTMS) and Orbitrap based metabolomics technology, its advantages and drawbacks for using in metabolomics and lipidomics studies, and development of novel approaches for processing HRMS data.

Annual banned-substance review: analytical approaches in human sports drug testing

The aim of improving anti-doping efforts is predicated on several different pillars, including, amongst others, optimized analytical methods. These commonly result from exploiting most recent developments in analytical instrumentation as well as research data on elite athletes' physiology in general, and pharmacology, metabolism, elimination, and downstream effects of prohibited substances and methods of doping, in particular. The need for frequent and adequate adaptations of sports drug testing procedures has been incessant, largely due to the uninterrupted emergence of new chemical entities but also due to the apparent use of established or even obsolete drugs for reasons other than therapeutic means, such as assumed beneficial effects on endurance, strength, and regeneration capacities. Continuing the series of annual banned-substance reviews, literature concerning human sports drug testing published between October 2014 and September 2015 is summarized and reviewed in reference to the content of the 2015 Prohibited List as issued by the World Anti-Doping Agency (WADA), with particular emphasis on analytical approaches and their contribution to enhanced doping controls.

Untargeted metabolomic analysis using LC-TOF/MS and LC-MS/MS for revealing metabolic alterations linked to alcohol-induced hepatic steatosis in rat serum and plasma

Untargeted LC-MS metabolomics to screen differential metabolites in rat serum and plasma, and reveal metabolic alterations linked to AHS.