Simplifying and expanding analytical capabilities for various classes of doping agents by means of direct urine injection high performance liquid chromatography high resolution/high accuracy mass spectrometry.

So far, in sports drug testing compounds of different classes are processed and measured using different screening procedures. The constantly increasing number of samples in doping analysis, as well as the large number of substances with doping related, pharmacological effects require the development of even more powerful assays than those already employed in sports drug testing, indispensably with reduced sample preparation procedures. The analysis of native urine samples after direct injection provides a promising analytical approach, which thereby possesses a broad applicability to many different compounds and their metabolites, without a time-consuming sample preparation. In this study, a novel multi-target approach based on liquid chromatography and high resolution/high accuracy mass spectrometry is presented to screen for more than 200 analytes of various classes of doping agents far below the required detection limits in sports drug testing. Here, classic groups of drugs as diuretics, stimulants, ß2-agonists, narcotics and anabolic androgenic steroids as well as various newer target compounds like hypoxia-inducible factor (HIF) stabilizers, selective androgen receptor modulators (SARMs), selective estrogen receptor modulators (SERMs), plasma volume expanders and other doping related compounds, listed in the 2016 WADA prohibited list were implemented. As a main achievement, growth hormone releasing peptides could be implemented, which chemically belong to the group of small peptides (<2kDa) and are commonly determined by laborious and time-consuming stand-alone assays. The assay was fully validated for qualitative purposes considering the parameters specificity, robustness (rRT: <2%), intra- (CV: 1.7-18.4 %) and inter-day precision (CV: 2.3-18.3%) at three concentration levels, linearity (R2>0.99), limit of detection (0.1-25ng/mL; 3'OH-stanozolol glucuronide: 50pg/mL; dextran/HES: 10µg/mL) and matrix effects.

Monitoring 2-phenylethanamine and 2-(3-hydroxyphenyl)acetamide sulfate in doping controls.

2-Phenylethanamine (phenethylamine, PEA) represents the core structure of numerous drugs with stimulant-like properties and is explicitly featured as so-called specified substance on the World Anti-Doping Agency (WADA) Prohibited List. Due to its natural occurrence in humans as well as its presence in dietary products, studies concerning the ability of test methods to differentiate between an illicit intake and the renal elimination of endogenously produced PEA were indicated. Following the addition of PEA to the Prohibited List in January 2015, retrospective evaluation of routine doping control data of 10 190 urine samples generated by combined gas chromatography-mass spectrometry and nitrogen phosphorus-specific detection (GC-MS/NPD) was performed. Signals for PEA at approximate concentrations > 500 ng/mL were observed in 31 cases (0.3%), which were subjected to a validated isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) test method for accurate quantification of the target analyte. Further, using elimination study urine samples collected after a single oral administration of 250 mg of PEA hydrochloride to two healthy male volunteers, two tentatively identified metabolites of PEA were observed and evaluated concerning their utility as discriminative markers for PEA intake. The ID-LC-MS/MS approach was extended to allow for the simultaneous detection of PEA and 2-(3-hydroxyphenyl)acetamide sulfate (M1), and concentration ratios of M1 and PEA were calculated for elimination study urine samples and a total of 205 doping control urine samples that returned findings for PEA at estimated concentrations of 50-2500 ng/mL. Urine samples of the elimination study with PEA yielded concentration ratios of M1/PEA up to values of 9.4. Notably, the urinary concentration of PEA did increase with the intake of PEA only to a modest extent, suggesting a comprehensive metabolism of the orally administered substance. Conversely, doping control urine samples with elevated (>50 ng/mL) amounts of PEA returned quantifiable concentrations of M1 only in 3 cases, which yielded maximum ratios of M1/PEA of 0.9, indicating an origin of PEA other than an orally ingested drug formulation. Consequently, the consideration of analyte abundance ratios (e.g. M1/PEA) is suggested as a means to identify the use of PEA by athletes, but further studies to support potential decisive criteria are warranted.

"Dilute-and-inject" multi-target screening assay for highly polar doping agents using hydrophilic interaction liquid chromatography high resolution/high accuracy mass spectrometry for sports drug testing.

In the field of LC-MS, reversed phase liquid chromatography is the predominant method of choice for the separation of prohibited substances from various classes in sports drug testing. However, highly polar and charged compounds still represent a challenging task in liquid chromatography due to their difficult chromatographic behavior using reversed phase materials. A very promising approach for the separation of hydrophilic compounds is hydrophilic interaction liquid chromatography (HILIC). Despite its great potential and versatile advantages for the separation of highly polar compounds, HILIC is up to now not very common in doping analysis, although most manufacturers offer a variety of HILIC columns in their portfolio. In this study, a novel multi-target approach based on HILIC high resolution/high accuracy mass spectrometry is presented to screen for various polar stimulants, stimulant sulfo-conjugates, glycerol, AICAR, ethyl glucuronide, morphine-3-glucuronide, and myo-inositol trispyrophosphate after direct injection of diluted urine specimens. The usage of an effective online sample cleanup and a zwitterionic HILIC analytical column in combination with a new generation Hybrid Quadrupol-Orbitrap® mass spectrometer enabled the detection of highly polar analytes without any time-consuming hydrolysis or further purification steps, far below the required detection limits. The methodology was fully validated for qualitative and quantitative (AICAR, glycerol) purposes considering the parameters specificity; robustness (rRT < 2.0%); linearity (R > 0.99); intra- and inter-day precision at low, medium, and high concentration levels (CV < 20%); limit of detection (stimulants and stimulant sulfo-conjugates < 10 ng/mL; norfenefrine; octopamine < 30 ng/mL; AICAR < 10 ng/mL; glycerol 100 µg/mL; ETG < 100 ng/mL); accuracy (AICAR 103.8-105.5%, glycerol 85.1-98.3% at three concentration levels) and ion suppression/enhancement effects.

Identification of black market products and potential doping agents in Germany 2010-2013.

PURPOSE: The desire to increase the athletic performance, to 'optimize' an individual's appearance, and to complement but also to arguably substitute exercise by means of drugs and drug candidates has generated a considerable (illicit) market for compounds such as anabolic-androgenic steroids, stimulants, growth promoting peptide hormones, and so on. Genuinely developed for therapeutic use, their abuse/misuse generates enormous health risks, which has necessitated comprehensive controls of compound trafficking by customs and anti-doping authorities. METHODS: From 2012 to 2013, the Bureau of Customs Investigation confiscated products containing anabolic-androgenic steroids (AAS; 259 kg), stimulants (13 kg), selective estrogen receptor modulators (SERMs; 24 kg), and human growth hormone (hGH; 3500 ampules). In cooperation with the Bureau and under the umbrella of the European Monitoring Center for Emerging Doping Agents (EuMoCEDA), the Cologne Anti-Doping Laboratory analyzed an additional 337 (black market) products between 2010 and 2013, allowing to monitor developments in drug use and, hence, the anticipation of new challenges in sports drug testing. Main tools utilized in characterizing confiscated materials were liquid chromatography-high resolution mass spectrometry (LC-HRMS), gas chromatography-high resolution mass spectrometry (GC-HRMS), and polyacrylamide gel electrophoresis (PAGE) with subsequent bottom-up identification of peptidic compounds using nano liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS). RESULTS: Among the 337 substances analyzed in the doping control laboratory in Cologne, 67 active ingredients were found, 49 of which being categorized as doping agents by the World Anti-Doping Agency (WADA). A total of 83.7 % accounted for steroidal substances (predominantly testosterone, trenbolone, and nandrolone and corresponding esters), 12.8 % accounted for peptide hormones and growth factors (predominantly hGH and growth hormone releasing peptides (GHRPs)), 3.2 % of the products contained hormones and metabolic modulators, and 0.3 % accounted for diuretic agents. Outstanding findings were the detection of the selective androgen receptor modulator (SARM) LGD-4033, the thymic hormone thymosin ß4, and a fusion protein of unknown biological activity. CONCLUSIONS: Trafficking of considerable amounts of arguably performance and/or body-enhancing compounds has been observed during the past 4 years, the majority of which is categorized as relevant to sports drug testing. Several substances are of fake/non-approved nature and represent enormous health risks to the 'customer'.

Doping control analysis of trimetazidine and characterization of major metabolites using mass spectrometric approaches.

Since January 2014, the anti-anginal drug trimetazidine [1-(2,3,4-trimethoxybenzyl)-piperazine] has been classified as prohibited substance by the World Anti-Doping Agency (WADA), necessitating specific and robust detection methods in sports drug testing laboratories. In the present study, the implementation of the intact therapeutic agent into two different initial testing procedures based on gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) is reported, along with the characterization of urinary metabolites by electrospray ionization-high resolution/high accuracy (tandem) mass spectrometry. For GC-MS analyses, urine samples were subjected to liquid-liquid extraction sample preparation, while LC-MS/MS analyses were conducted by established 'dilute-and-inject' approaches. Both screening methods were validated for trimetazidine concerning specificity, limits of detection (0.5-50 ng/mL), intra-day and inter-day imprecision (<20%), and recovery (41%) in case of the GC-MS-based method. In addition, major metabolites such as the desmethylated trimetazidine and the corresponding sulfoconjugate, oxo-trimetazidine, and trimetazidine-N-oxide as identified in doping control samples were used to complement the LC-MS/MS-based assay, although intact trimetazidine was found at highest abundance of the relevant trimetazidine-related analytes in all tested sports drug testing samples. Retrospective data mining regarding doping control analyses conducted between 1999 and 2013 at the Cologne Doping Control Laboratory concerning trimetazidine revealed a considerable prevalence of the drug particularly in endurance and strength sports accounting for up to 39 findings per year.

Isotope-dilution mass spectrometric quantification of the prodrug lisdexamfetamine in human urine in doping control analysis.

RATIONALE: Therapeutic approaches concerning attention-deficit hyperactivity disorder (ADHD) commonly include the administration of drugs amplifying cerebral dopamine and norepinephrine signals. Among these, compounds belonging to the Prohibited List as established by the World Anti-Doping Agency (WADA) are present such as amfetamine or methylphenidate, and abuse of these can result in sanctions for athletes. The recently approved therapeutic lisdexamfetamine represents a slow-release prodrug of amfetamine for ADHD treatment. In order to support doping control laboratories in differentiating the abuse of amfetamine from a therapeutic administration of lisdexamfetamine, the determination of the prodrug from urine is desirable. Since approximately 2% of lisdexamfetamine are eliminated intact into urine, a liquid chromatography/high-resolution/high accuracy mass spectrometric method was developed, allowing the target analyte and one of its metabolites (4-hydroxyamfetamine sulfate) to be accurately quantified. METHODS: Urine samples were fortified with fourfold deuterated lisdexamfetamine and analyzed directly using ultrahigh-performance liquid chromatography (UHPLC) interfaced via electrospray ionization to a second-generation quadrupole-orbitrap mass spectrometer. The assay was characterized concerning specificity, limits of quantification (0.15-5 ng/mL), intraday and interday imprecision (4-22%), accuracy (90-120%), linearity, and ion suppression/enhancement effects. A patient's urine samples were analyzed to provide proof-of-principle data demonstrating that the intact prodrug lisdexamfetamine is detectable in urine up to 11 h post-administration at concentrations up to 80 ng/mL. Moreover, amfetamine and sulfoconjugated 4-hydroxyamfetamine were measured, yielding up to 1146 and 56 ng/mL, respectively. CONCLUSIONS: Considering the observed comparably low urinary concentrations of lisdexamfetamine and 4-hydroxyamfetamine sulfate, the preferred minimally labor-intense sample preparation, and the necessity of fast and robust result generation, the employed instrumental setup proved fit-for-purpose in sports drug testing.

Sports drug testing: Analytical aspects of selected cases of suspected, purported, and proven urine manipulation.

Manipulation of urine specimens provided by elite athletes for doping control purposes has been reported several times in the past, and in most of these cases urine substitution was eventually proven. Recent findings of suspected and substantiated manipulation have outlined the complexity and diversity of tampering options, sample appearance alterations resulting from non-manipulative influence, and the analytical challenges arising from these scenarios. Using state-of-the-art mass spectrometric and immunological doping control and forensic chemistry methodologies, four unusual findings were observed. One sports drug testing specimen was found to contain an unusually high content of saccharides accompanied by hordenine and Serpine-Z4, while no endogenous steroid (e.g. testosterone, epitestosterone, androsterone and etiocholanolone) was detected. This specimen was identified as non-alcoholic beer filled into the doping control sample container, constituting an undisputed doping offense. A doping control sample of bright green color was received and found to contain residues of methylene blue, which is not considered relevant for doping controls as no masking or manipulative effect is known. In addition, the number of urine samples of raspberry to crimson red coloration received at doping control laboratories has constantly increased during the last years, attributed to the presence of hemoglobin or betanin/isobetanin. Also here, no doping rule violation was given and an impact on routine analytical results was not observed. Finally, a total of 8 sports drug testing samples collected at different competition sites was shown to contain identical urine specimens as indicated by steroid profile analysis and conclusively proven by DNA-STR (short tandem repeat) analysis. Here, the athletes in question were not involved in the urine substitution act but the doping control officer was convicted of sample manipulation.

Analysis of octopamine in human doping control samples.

The biogenic amine octopamine [4-(2-amino-1-hydroxyethyl)phenol] is prohibited in sports owing to its stimulating and performance-enhancing properties. Adverse analytical findings in athletes' doping control samples commonly result from surreptitious applications; however, the occurrence of octopamine in nutritional supplements and in selected invertebrates as well as the assumption that its N-methylated analog synephrine [4-(1-hydroxyethyl-2-methylamino)phenol, not banned by anti-doping authorities but currently monitored in prevalence studies) might be converted in-vivo into octopamine have necessitated a study to investigate the elimination of synephrine and octopamine present in over-the-counter products. Urine samples collected after administration of nutritional supplements containing octopamine and/or synephrine as well as urine samples collected after therapeutic application of octopamine- or synephrine-containing drugs were analyzed using a validated solid-phase extraction-based procedure employing a weak cation exchange resin and liquid chromatographic/tandem mass spectrometric detection with electrospray ionization and multiple reaction monitoring. In the case of therapeutic octopamine application, the urinary concentration of the target compound increased from baseline levels below the lower limit of detection to 142 µg/mL, while urine samples collected after synephrine as well as dietary supplement administration did not yield any evidence for elevated renal excretion of octopamine.

Screening for benfluorex and its major urinary metabolites in routine doping controls.

Benfluorex [1-(m-trifluoromethylphenyl)-2-(ß-benzoyloxyethyl)aminopropane] has been widely used for the treatment of atherogenic metabolic disorders and impaired carbohydrate metabolism (particularly in obese type-II diabetic patients) as well as an anorectic drug. Due to its potentially performance-enhancing properties, benfluorex has been added to the list of prohibited compounds and methods of doping by the World Anti-Doping Agency (WADA) in 2010, necessitating the implementation of the drug as well as its major metabolites into routine doping control procedures. In the present study, human urinary metabolites of benfluorex were characterized by gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) as well as liquid chromatography-electrospray ionization-high resolution/high accuracy tandem mass spectrometry (LC-ESI-MS/MS). Commonly employed sports drug testing approaches consisting of liquid-liquid extraction followed by GC-MS or urine dilution and immediate LC-MS/MS analysis were expanded and validated with regard to specificity, recovery (48-54%, GC-MS only), intra- and interday precision (<25%), limits of detection (5-8 ng/mL for LC-MS/MS and 80 ng/mL for GC-MS), and ion suppression (for LC-ESI-MS/MS only) to allow the detection of benfluorex metabolites 1-(m-trifluoromethylphenyl)-2-(2-hydroxyethyl)aminopropane (M1), 1-(m-trifluoromethylphenyl)-2-(2-carboxymethyl)aminopropane (M2), and 1-(m-trifluoromethylphenyl)-2-aminopropane (M3) as well as the glucuronic acid conjugate of M1.

Stimulants and doping in sport.

Stimulants have been frequently detected in doping control samples and represent a structurally diverse class of compounds. Comprehensive sports drug-testing procedures have been developed using gas or liquid chromatography combined with mass spectrometric detection, and they have revealed various adverse analytical findings, as demonstrated with 2 examples, 4-methylhexan-2-amine and methoxyphenamine. Moreover, the necessity of controlling the use or misuse of stimulating agents is outlined by means of pseudoephedrine, a compound that was prohibited in sports until the end of 2003. Since the ban was lifted, monitoring programs proved a significant increase in pseudoephedrine applications as determined from urine samples collected in competition. As a consequence, a reimplementation of this drug in future doping controls was decided.

Doping control analysis of metamfepramone and two major metabolites using liquid chromatography-tandem mass spectrometry.

The sympathomimetic agent metamfepramone (2-dimethylamino-1-phenylpropan-1-one, dimethylpropion) is widely used for the treatment of the common cold or hypotonic conditions. Due to its stimulating properties and its rapid metabolism resulting in major degradation products such as methylpseudoephedrine and methcathinone, it has been considered relevant for doping controls by the World Anti-Doping Agency (WADA). The rapid degradation of the active drug complicates the detection of metamfepramone itself but the metabolites methylpseudoephedrine and methcathinone can be monitored, and the finding of the latter in particular allows the inference of a metamfepramone administration. In order to improve sports drug testing procedures, metamfepramone, methylpseudoephedrine and methcathinone were characterized using electrospray ionization-high resolution/high accuracy mass spectrometry, and a method employing liquid chromatography/tandem mass spectrometry was established that allowed the analysis of these three analytes by direct injection of 2 microL of urine specimens. The assay was validated with regard to specificity, lower limits of detection (2-10 ng mL(-1)), intraday and interday precision (3-17%) and ion suppression/enhancement effects. The developed procedure has been used to verify or falsify suspicious signals observed in routine screening procedures based on gas chromatography/mass spectrometry and yielded an adverse analytical finding concerning a metamfepramone administration in an authentic doping control sample. Although the active drug was not detected, the indicative metabolites methylpseudoephedrine and methcathinone were considered sufficient to infer the application of the prohibited drug.

Determination of selected stimulants in urine for sports drug analysis by solid phase extraction via cation exchange and means of liquid chromatography-tandem mass spectrometry.

Stimulatory substances applied during competition possess a reasonable potential as performance enhancing agents and their misuse in elite sport has been frequently reported during the last few decades. An analytical method for the qualitative determination of selected stimulants containing a primary or secondary amine moiety in human urine for doping control purposes was developed. A rapid and highly specific procedure based on a sample preparation using weak cation exchange solid phase extraction (SPE-XCW) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with a C6-Phenyl analytical column allowed the unambiguous identification of the target analytes down to low ng mL(-1) concentration levels. Validation provided recovery rates of better than 75%, precisions of less than 20% and a linear approximation in the required working range (10-750 ng mL(-1)) were obtained for 19 different target compounds. This method provides a rugged and highly specific alternative to the established method utilising gas or liquid chromatography after liquid-liquid extraction.

Doping control analysis of methoxyphenamine using liquid chromatography-tandem mass spectrometry.

Methoxyphenamine (o-methoxy-N,alpha-dimethylphenethylamine, Orthoxine) used in earlier times as a bronchodilator is prohibited in sports according to the regulations of the World Anti-Doping Agency (WADA). The drug and several of its metabolites are commonly analysed in doping control screening assays using gas chromatography-mass spectrometry requiring extraction from urine specimens. A complementary method employing liquid chromatography-atmospheric pressure chemical ionisation-tandem mass spectrometry and direct injection of urine aliquots was developed, which provided a fast and sensitive alternative to confirm the presence of the prohibited compound and degradation products in sports drug testing samples. In particular, the chromatographic separation of the active drug from isomeric compounds such as the designer drug p-methoxymetamphetamine (PMMA) was of particular interest to unambiguously identify the applied substance and was accomplished using a C6-phenyl reverse-phase column with isocratic elution. The established procedure was validated for methoxyphenamine with regard to specificity, limit of detection (0.7 ng mL(-1)), intraday- and interday precision (2.5-5.8% and 10.8-16.2%, respectively) and its applicability was demonstrated with an authentic doping control sample which tested positive for the prohibited compound early in 2008.

Determination of the prevalence of anabolic steroids, stimulants, and selected drugs subject to doping controls among elite sport students using analytical chemistry.

Drug abuse by adolescents has been investigated in various surveys that reported correlations between age, gender, and activity. However, none of these studies included chemical analyses to help substantiate the statements of participants. In the present study, the urine specimens of 964 students (439 females, 525 males; mean age 22.1 years, s = 1.7), who applied to study sports sciences at university, were assessed for anabolic steroids, stimulants, and selected drugs prohibited in sports. In total, 11.2% of the urine specimens provided contained drugs covered by doping controls. The most frequently detected compound was the major metabolite of tetrahydrocannabinol (9.8%) followed by various stimulants related to amphetamine and cocaine (1.0%). Indications of anabolic steroid use were found in 0.4% of urine samples but originated from contraceptives containing norethisterone. The present study provided unambiguous data on the status quo of drug (ab)use by adolescents hoping for a career related to elite sport or sports sciences. No use of anabolic steroids was detected. However, evidence for stimulants and tetrahydrocannabinol administration was obtained, although not reported by any participant, which highlights the issue of under-reporting in surveys based solely on questionnaires.

Analysis of confiscated black market drugs using chromatographic and mass spectrometric approaches.

In the context of house searches in Germany, numerous drugs were confiscated and subjected to chemical analysis, including anabolic agents such as various anabolic-androgenic steroids (stanozolol, testosterone derivatives, trenbolone esters, etc.) and clenbuterol, as well as agents with anti-estrogenic activity (tamoxifen, clomiphene), drugs stimulating virility (sildenafil, tadalafil), and unlabeled plastic bags. Liquid chromatography-tandem mass spectrometry, gas chromatography-mass spectrometry with nitrogen-phosphorus specific detection, gel electrophoresis, and immunological tests were employed to test for the effective content of 70 products. In 18 cases (25.7%), the declared ingredients differed from the actual content, in particular concerning anabolic-androgenic steroids. Nandrolone and trenbolone esters, for instance, were frequently substituted or complemented by various testosterone derivatives, and several testosterone depot formulations originally composed of four different esters were found to contain fewer or wrong components. Except for those drugs supposedly originating from so-called underground labs, fake packings were hardly or not distinguishable from original boxes by visual inspection.

Determination of tuaminoheptane in doping control urine samples.

Since January 2007, the list of prohibited substances established by the World Anti-Doping Agency includes the sympathomimetic compound tuaminoheptane (1-methyl-hexylamine, 2-heptylamine). Primarily used as nasal decongestant drug it has been considered relevant for sports drug testing due to its stimulating properties. A confirmatory gas chromatographic-mass spectrometric procedure was developed including liquid-liquid extraction and imine formation of tuaminoheptane employing various aldehydes and ketones such as formaldehyde, acetaldehyde, benzaldehyde and acetone. Extraction and derivatisation conditions were optimised for utmost efficiency, and characteristic fragment ions obtained after electron ionisation allowed for a sensitive and selective analytical assay, which was validated with regard to recovery (50%), lower limit of detection (20 ng mL(-1)) as well as interday- and intraday precision (<15%). The applicability to authentic urine samples was demonstrated using administration study specimens obtained from two male persons using Rhinofluimucil (tuaminoheptane hemisulfate) for intranasal application. The administered drug was detected up to 46 h after repeated topical instillation of a total of approximately 3 mg.

Detection of manipulation in doping control urine sample collection: a multidisciplinary approach to determine identical urine samples.

Manipulation of urine sampling in sports drug testing is considered a violation of anti-doping rules and is consequently sanctioned by regulatory authorities. In 2003, three identical urine specimens were provided by three different athletes, and the identity of all urine samples was detected and substantiated using numerous analytical strategies including gas chromatography-mass spectrometry with steroid and metabolite profiling, gas chromatography-nitrogen/phosphorus detector analysis, high-performance liquid chromatography-UV fingerprinting, and DNA-STR (short tandem repeat) analysis. None of the respective athletes was the donor of the urine provided for doping analysis, which proved to be a urine sample collected from other unidentified individual(s). Samples were considered suspicious based on identical steroid profiles, one of the most important parameters for specimen individualization in sports drug testing. A database containing 14,224 urinary steroid profiles of athletes was screened for specific values of 4 characteristic parameters (ratios of testosterone/epitestosterone, androsterone/etiocholanolone, androsterone/testosterone, and 5alpha-androstane-3alpha,17beta-diol/5beta-androstane-3alpha,17beta-diol) and only the three suspicious samples matched all criteria. Further metabolite profiling regarding indicated medications and high-performance liquid chromatography-UV fingerprinting substantiated the assumption of manipulation. DNA-STR analyses unequivocally confirmed that the 3 urine samples were from the same individual and not from the athletes who provided DNA from either buccal cell material or blood specimens. This supportive evidence led to punishment of all three athletes according to the rules of the World Anti-Doping Agency. Application of a new multidisciplinary strategy employing common and new doping control assays enables the detection of urine substitution in sports drug testing.

Determination of N-desmethyl- and N-bisdesmethyl metabolites of Sibutramine in doping control analysis using liquid chromatography-tandem mass spectrometry.

Since January 2006, the list of prohibited substances established by the World Anti-Doping Agency includes the antidepressant / anti-obesity drug Sibutramine. Due to its rapid degradation to its active metabolites N-desmethyl and N-bisdesmethyl Sibutramine, reference compounds were synthesized and included into an existing screening assay to allow the unambiguous determination of these metabolic products in human urine using liquid-liquid extraction followed by liquid chromatography/tandem mass spectrometry. Characteristic product ions, obtained after electrospray ionization and collision-induced dissociation, were elucidated using high resolution/high accuracy mass measurements with a hybrid linear ion trap/orbitrap mass analyzer. Based on diagnostic product ions, the extended screening procedure was validated for both Sibutramine metabolites using a triple quadrupole mass spectrometer. Items such as lower limits of detection (6-40 ng mL(-1)), recoveries (39-42%), intraday precision (low: 5.5-10.6%, medium: 4.9-5.9%), high: 12.8-16.4%) and interday precision (low: 15.0-22.8%, medium: 17.7-18.6%), high: 16.5-25.6%) were evaluated, and a clinical spot urine sample was analyzed to demonstrate the applicability of the developed assay in sports drug testing.