Time filter

Source Type

Thomas A.,German Sport University Cologne | Kohler M.,German Sport University Cologne | Mester J.,German Sport University Cologne | Geyer H.,German Sport University Cologne | And 3 more authors.
Drug Testing and Analysis | Year: 2010

Black market products of a pharmaceutical nature and nutritional supplements have received substantial and increasing attention because of potential performance enhancement in elite and non-professional sports. In addition, improved general health is claimed for non-competing individuals. The risks and foreseeable dangers of the uncontrolled use of highly potent and non-approved pharmaceutical compounds in healthy individuals are of considerable concern. In the present case report, the emerging drug candidate GHRP-2 with verified growth-hormone-releasing properties was identified and quantified in tablets offered as an over-the-counter nutritional supplement. The impact of this orally active peptide on the hGH/IGF-axis has been established for several years and its illicit use in elite sports has been assumed. As a releasing factor for hGH, GHRP-2 belongs to the list of substances prohibited by the World Anti-Doping Agency (WADA). Unfortunately, to date there is no routinely performed assay for the determination of these peptides potentially occurring in biological fluids of competing athletes, but the present data will facilitate the implementation by providing principle analytical information on liquid chromatographic and mass spectrometric behaviour. Qualitative identification of the target analyte after extraction from the tablet matrix was performed by high resolution/high accuracy mass spectrometry after liquid chromatographic separation under consideration of the accurate masses and the ratios of the protonated molecules and their fragment ions derived from their collisionally induced dissociation. Quantitative results were obtained by means of liquid chromatography coupled to a triple quadrupole mass spectrometer and linear regression using an external calibration curve (with GHRP-2 reference compound) adjusted via internal standard (Hexarelin). Hereby, the content of GHRP-2 was determined with approximately 50 μg per tablet. Copyright © 2010 John Wiley & Sons, Ltd.

Thomas A.,German Sport University Cologne | Hoppner S.,German Sport University Cologne | Geyer H.,German Sport University Cologne | Schanzer W.,German Sport University Cologne | And 4 more authors.
Analytical and Bioanalytical Chemistry | Year: 2011

A family of small peptides has reached the focus of doping controls representing a comparably new strategy for cheating sportsmen. These growth hormone releasing peptides (GHRP) are orally active and induce an increased production of endogenous growth hormone (GH). While the established test for exogenous GH fails, the misuse of these prohibited substances remains unrecognized. The present study provides data for the efficient extraction of a variety of known drug candidates (GHRP-1, GHRP-2, GHRP-4, GHRP-5, GHRP-6, alexamorelin, ipamorelin, and hexarelin) from human urine with subsequent mass spectrometric detection after liquid chromatographic separation. The used method potentially enables the retrospective evaluation of the acquired data for unknown metabolites by means of a non-targeted approach with high-resolution/high-accuracy full-scan mass spectrometry with additional higher collision energy dissociation experiments. This is of great importance due to the currently unknown metabolism of most of the targets and, thus, the method is focused on the intact peptidic drugs. Only the already characterised major metabolite of GHRP-2 (d-Ala-d-2-naphthylAla-l-Ala, as well as its stable isotope-labelled analogue) was synthesised and implemented in the detection assay. Method validation for qualitative purpose was performed with respect to specificity, precision (<20%), intermediate precision (<20%), recovery (47-95%), limit of detection (0.2-1 ng/mL), linearity, ion suppression and stability. Two stable isotope-labelled internal standards were used (deuterium-labelled GHRP-4 and GHRP-2 metabolite). The proof-of-principle was obtained by the analysis of excretion study urine samples obtained from a single oral administration of 10 mg of GHRP-2. Here, the known metabolite was detectable over 20 h after administration while the intact drug was not observed. © 2011 Springer-Verlag.

Thomas A.,German Sport University Cologne | Guddat S.,German Sport University Cologne | Kohler M.,German Sport University Cologne | Krug O.,German Sport University Cologne | And 3 more authors.
Rapid Communications in Mass Spectrometry | Year: 2010

Occasionally, doping analysis has been recognized as a competitive challenge between cheating sportsmen and the analytical capabilities of testing laboratories. Both have made immense progress during the last decades, but obviously the athletes have the questionable benefit of frequently being able to switch to new, unknown and untested compounds to enhance their performance. Thus, as analytical counteraction and for effective drug testing, a complementary approach to classical targeted methods is required in order to implement a comprehensive screening procedure for known and unknown xenobiotics. The present study provides a new analytical strategy to circumvent the targeted character of classical doping controls without losing the required sensitivity and specificity. Using 50mL of plasma only, the method potentially identifies illicit drugs in low ng/mL concentrations. Plasma provides the biological fluid with the circulating, unmodified xenobiotics; thus the identification of unknown compounds is facilitated. After a simple protein precipitation, liquid chromatographic separation and subsequent detection by means of high resolution/high accuracy orbitrap mass spectrometry, the procedure enables the determination of numerous compounds from different classes prohibited by the World Anti-Doping Agency (WADA). A new hyphenated mass spectrometry technology was employed without precursor ion selection for higher collision energy dissociation (HCD) fragmentation experiments. Thus the mass spectra contained all the desired information to identify unknown substances retrospectively. The method was validated for 32 selected model compounds for qualitative purposes considering the parameters specificity, selectivity, limit of detection (<0.1-10ng/mL), precision (9-28%), robustness, linearity, ion suppression and recovery (80-112%). In addition to the identification of unknown compounds, the plasma samples were simultaneously screened for known prohibited targets. © 2010 John Wiley & Sons, Ltd.

Kohler M.,German Sport University Cologne | Thomas A.,German Sport University Cologne | Geyer H.,German Sport University Cologne | Petrou M.,Makario Athletic Center Avenue | And 2 more authors.
Drug Testing and Analysis | Year: 2010

Doping control laboratories are frequently confronted with new substances that may be misused by athletes. Besides new pharmaceuticals, where method development for their detection is dependant on the availability of the substance and corresponding administration studies, some professional and amateur athletes are using illicit 'black market' products, which either differ from known pharmaceuticals but cause similar effects or still are undergoing clinical trials and are therefore rarely available to doping control laboratories. In the Cologne Doping Control Laboratory, different confiscated products and legally obtained nutritional supplements were analyzed in 2009, and various findings were reported including GH-labelled injection vials without any pharmacologically active content; combinations of products indicating the attempt to mask growth hormone abuse; unpurified long-R3-IGF-1; nutritional supplements containing the growth hormone releasing peptide-2 (GHRP-2); and ampoules containing the selective androgen receptor modulator Andarine (S-4). This review provides an overview on the substances that were analyzed in 2009. Ingredients relevant for doping control were identified by means of liquid chromatography and mass spectrometry methods. The awareness of new products on the black market and in nutritional supplements is of utmost importance for laboratories to develop detection methods accordingly and screen for new substances as early as possible. © 2010 John Wiley & Sons, Ltd.

Loading Makario Athletic Center Avenue collaborators
Loading Makario Athletic Center Avenue collaborators