Abstract Bachelor Project FBT 2018-2019: OPTIMIZATION OF SAMPLE PREPARATION FOR THE CONFIRMATION OF DOPING IN URINE USING GC-MS
Doping control happens in two stages: a screening stage and a confirmation stage. Today only one pH and solvent are used to extract doping products. Also, some products extract better in a basic environment and some in a more acidic environment. Because doping control makes use of many low concentrations, an as high as possible extraction recovery is needed. To get this highest recovery a different extraction solvent and pH could be needed. The focus of this study is to find the best solvent and pH for each component that is prohibited in sports for analyses with the gas chromatography-mass spectrometry. These components are extracted with a liquid-liquid extraction, derivatized and analyzed with the time of flight gas chromatography-mass spectrometry.
The different solvents used are:
- Methyl tert-buthyl ether (MTBE)
The different pHs used are:
These combination test showed the following solvent and pH give the best results. These results are generalized and there are a few exceptions.
- Anabolic agents: MTBE and pH 9,5
- Beta-2 Agonist: MTBE and pH 9,5
- Hormone and metabolic modulators: A lot of variation for each compound
- Diuretics: MTBE and pH vary a lot
- Stimulants: Ethyl acetate or MTBE and a pH 9,5 or 14
- Narcotics: MTBE and pH 9,5
- Others: MTBE and pH 9,5
Not all prohibited substances were tested in this short period or showed a good result and need to be retested. In total 62 of the 77 tested products are optimized, although a lot more products need to be investigated.
Abstract bachelorproef 2016-2017: Direct detection of testosterone esters in sports, Development of an ultra-sensitive GC/MSMS method for the detection of testosterone esters in blood plasma
The goal of this study was to develop an ultra-sensitive method for detecting T esters in blood plasma. The reason for the development is, that the detection of an intact ester of testosterone could lead towards unequivocal proof of misuse through administration of the exogenous testosterone.
In this study, an ultra-sensitive detection method was created on GC/MSMS including a custom sample preparation protocol. In our study protocol a liquid-liquid extraction (LLE) was used for the sample clean-up. Furthermore the use of a HPLC with a fraction collector was used to exclude the samples of cholesterol.
After the method development, it was validated according to the in-house validation protocol of DoCoLab.
The method was then tested on blood samples of 12 volunteers. These were collected in a Nebido® study. In this study volunteers were injected with a single dose of 1g of Nebido®, a drug containing T undecanoate. After the administration, blood samples were collected over a time period of 3 months.
Through this method it was possible to detect T undecanoate between 32 and 86 days. This is a similar result as the available methods in up-to-date literature. In the future the interference of cholesterol could be eliminated which would result in clean and better compound response. Still the method can detect 8 other T esters, so it could be used as direct method which in the future could result in a standalone detection method or as a confirmation test. As a confirmation test it could replace the more expensive analysis with GC/C/IRMS, which would lower the cost and expensive for the analyst and the client.
9052 Zwijnaarde (Gent)
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Prof. Peter Van Eenoo
Pieter Van Renterghem