The death of Victor Conte last week, founder of the BALCO lab at centre of a massive steroid scandal, has brought back lots of memories of that time period. I was working in the London WADA lab at the time and it was quite exciting to be in the midst of it all.
For a reminder, the scandal involved the biggest baseball star of the time, along with many of the world’s fastest sprint athletes of the time – http://news.bbc.co.uk/sport1/hi/front_page/4067449.stm
There athletes were reported to have taken several different drugs in this programme, but the one that was most interesting was known as ‘The Clear’. This was the name due to the fact it could not be detected in drug testing. So lets take a look.
The Clear – THG
The image above (hastily drawn on the train, apologies) shows the synthetic steroid Gestrinone (left). Gestrinone is a prescription drug and listed on the WADA Prohibited list as an Anabolic Androgenic Steroid. The right hand figure is tetrahydrogestrinone (THG), a very similar anaoluge of gestrinone. however, this was not known of or listed in the WAD regulations. When it was discovered it was classed as an analogue and confirmed as being banned. For some time before it was discovered though, it was not being detected, so clear.
Why was it not detected? The difference is little, and for a non chemist very subtle. The TH part of THG refers to tetrahydro – which means four hydrogens. So it is gestrinone with four hydrogens added. This can be seen at the top of the molecule where G has a triple bond, which is a single bond on THG (ringed with dots on both substances). The fact that THG has four additional hydrogens means that the molar mass of THG (312 g/mol) is four higher than gestrinone (308 g/mol, each hydrogen added increases the mass by 1). The detection method at the time was gas chromatography coupled with mass spectrometry (GC-MS). The MS part was set to look for molecules of a particular mass, filtering others out. The list it could see was extensive, and included gestrinone, but not the mass for THG. This meant it wasn’t seen, hence The Clear! Seemingly so subtle difference but yet evaded detection for some time.
The whole story was very interesting, leading to jail, Olympic bans and much more. I just thought the science of why it was ‘Clear’ was also of interest.
Thanks for reading!