Chromatography Unmasks the Masking Agent — Drug Cheats Watch Out!

The world of sport seems to be going through turbulent times. Whenever we witness a great sporting highlight on the sport’s pages — you can guarantee that the back pages will soon, once again, be filled with allegations of cheating or a drug scandal.

The latest claims continue the recent themes of allegations against drug testing labs and people being caught out with nutritional supplements. 2016 is an Olympic year — with the summer games taking place in Rio against a backdrop of drug allegations and the continuing worry surrounding the Zika virus.

But a recent study might give a boost to all those who like their sport clean — and chromatography was again a key element.

Win at any cost

With the rewards for cheating and winning in professional sport so high, it is easy to see why some people seek any advantage. But with most sports now using some kind of drug testing regime — either new drugs have to be found or a way to mask existing drugs has to be used.

The World Anti-Doping Agency (WADA) lists all the drugs that are prohibited in different sports. Whilst many people are aware of substances like steroids and other performance enhancing substances, WADA also includes medicines that are used by drug cheats — vaptans are one class of medicine used as a cheat’s best friend.

Masking the drugs

To avoid detection, drug cheats need to pass a urine test — with samples taken during training regimes and at major competitions. There are essentially two ways for a cheat to pass the test — take the drug early enough so it has passed through the system or mask the drug.

One type of drug commonly used as a masking agent is tolvaptan — part of the class of drugs known as vaptans that are diuretics and can be used to treat heart and kidney disease. Tolvaptan acts to remove excess fluids from the body, thereby increasing the flow of urine. As drugs and their metabolites are excreted in urine — hence why urine tests are used for athletes — the masking agents can help rid the body quickly of an illegal drug and its metabolites.

Can’t hide from HPLC-MS

A recent study — carried out by the Norwegian Doping Control Laboratory and reported in Drug Testing and Analysis — reports on a method that could help detect the use of the masking agent tolvaptan. The team developed a method to detect the masking agent using high performance liquid chromatography linked to mass spectrometry and managed to detect not just tolvaptan —but perhaps more importantly — its metabolites which have a longer life in the body and so are more likely to be in a sample.

Using HPLC-MS for drug testing in urine is used in many laboratories. But a move to using non-invasive techniques is a possibility as discussed in the article, Using Micro-Elution SPE to Accelerate Sample Preparation for the Determination of Cannabis Use.

Does being a clean athlete matter to you?