Gerd Sigmund

High-throughput screening for various classes of doping agents using a new ‘dilute-and-shoot’ liquid chromatography-tandem mass spectrometry multi-target approach

A new multi-target approach based on liquid chromatography--electrospray ionization tandem mass spectrometry (LC-(ESI)-MS/MS) is presented to screen for various classes of prohibited substances using direct injection of urine specimens. With a highly sensitive new generation hybrid mass spectrometer classic groups of drugs--for example, diuretics, beta2-agonists--stimulants and narcotics are detectable at concentration levels far below the required limits. Additionally, more challenging and various new target compounds could be implemented. Model compounds of stimulant conjugates were studied to investigate a possible screening without complex sample preparation. As a main achievement, the integration of the plasma volume expanders dextran and hydroxyethyl starch (HES), commonly analyzed in time-consuming, stand-alone procedures, is accomplished. To screen for relatively new prohibited compounds, a common metabolite of the selective androgen receptor modulator (SARMs) andarine, a metabolite of growth hormone releasing peptide (GHRP-2), and 5-amino-4-imidazolecarboxyamide ribonucleoside (AICAR) are analyzed. Following a completely new approach, conjugates of di(2-ethylhexyl) phthalate (DEHP) metabolites are monitored to detect abnormally high levels of plasticizers indicating for illicit blood transfusion. The assay was fully validated for qualitative purposes considering the parameters specificity, intra- (3.2-16.6%) and inter-day precision (0.4-19.9%) at low, medium and high concentration, robustness, limit of detection (1-70 ng/ml, dextran: 30 µg/ml, HES: 10 µg/ml) and ion suppression/enhancement effects. The analyses of post-administration and routine doping control samples demonstrates the applicability of the method for sports drug testing. This straightforward and reliable approach accomplishes the combination of different screening procedures resulting in a high-throughput method that increases the efficiency of the labs daily work.

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.

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

Abstract 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.

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.

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.

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.

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 a 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 46h after repeated topical instillation of a total of approximately 3 mg.

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

Methoxyphenamine (o-methoxy-N,α-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.

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 μL 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.

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.