Despite frequent testing, detecting drugs in blood and urine can be challenging because they can be metabolized quickly. And since new drugs are coming out all the time, the latest ones may not be tested for in time.

Vacuum to the rescue

The World Anti-Doping Agency (WADA) certifies laboratories to test for drugs. These labs rely primarily on a combination of gas chromatography and mass spectrometry. Using vacuum, this technology can detect even tiny traces of a few picograms or femtograms per milliliter of urine.

First, the tester uses a high vacuum to evaporate samples and separate them into individual substances. Then, the mass spectrometer sorts them according to mass and charge. The unknown compounds are ionized first, most often by electron impact ionization. Some of the molecules disintegrate into charged fragments. The resulting ions are now accelerated, pass through an electric and magnetic field and finally hit the detector.

The whole process takes place in a high vacuum so that the ions are not scattered by the collision with air molecules and deflected from their path to the detector. Vacuum Systems ensure a constant negative pressure of one-millionth of a millibar at the most during the analyses.

As soon as the detector registers signals, spectra corresponding to the specific mass of the molecules and fragments are recorded. Special software and databases are used to help with interpretation. This allows conclusions about the substances contained in the sample to be drawn from the different peak values and the concentration of these substances to be calculated. It is then possible to use this to derive whether a limit value has been exceeded.