Unraveling the complexity of anti-doping analysis: reassessing meldonium detection and doping verdicts in a case study.

BACKGROUND: The precision and accuracy of mass spectrometry (MS) made it a fundamental tool in anti-doping analysis. High-resolution (HR) mass spectrometers significantly improved compound identification. This study systematically analyzes data from an athlete (Subject 1) who tested positive for meldonium and compares it with data from a healthy volunteer (Subject 2) to examine the correctness of the doping verdict. CASE PRESENTATION: The documentation related to Subject 1 was thoroughly processed and analyzed. A study involving a volunteer (Subject 2) replicated Subject 1 regimen and urine sample collection for data alignment with anti-doping results, with Subject 2 reporting not using meldonium. The anti-doping agency's analysis of Subject 1 showed the presence of meldonium at a concentration close to the established cut-off level. However, a closer examination revealed that one specific ion, crucial for meldonium identification, was absent from the mass spectra. Analyzing Subject 2 data, using the same methodology, the absence of the specific ion was confirmed, even though the volunteer did not consume meldonium. The European directive and the method that was validated and cited by the anti-doping agency identified meldonium on at least four specific ions, whereas the anti-doping analysis used only three ions. This discrepancy compromises the specificity of meldonium identification. CONCLUSIONS: To enhance the analytical methodology, two strategic interventions are suggested: adjusting the meldonium cut-off value and expanding the analysis to include meldonium metabolites. By addressing these avenues, the precision of meldonium detection and doping verdicts can be improved. In conclusion, this study challenges the anti-doping agency's verdict and prompts a reevaluation of meldonium detection methodologies in anti-doping measures.

The iridium/iridium oxide electrode for in vivo measurement of oesophageal and gastric pH.

An iridium-iridium oxide electrode for in vivo pH measurement of the distal oesophagus is described. It is small and flexible so it is well accepted by patients for long-term pH monitoring. The electrode also offers the possibility of including another electrode and/or a pressure sensor for simultaneous detection of two or more parameters--gastric pH or oesophageal pressure for example. A clinical study was performed on 15 healthy volunteers and the results were checked on a DGC Nova 4/S computer, showing less than 0.005% of tension in mV out of the established range in a period of 24 h pH monitoring. The volunteers' results were compared with the normal values obtained by DeMeester using a glass electrode on a similar, healthy group of American patients and no significant differences were observed. Owing to its small size, reliability, fast response to pH changes, durability and its easy storage, the Ir/IrO2 electrode is ideal for long-term pH monitoring of the upper gastro-intestinal tract.