Drugs in the environment
The development of more sensitive analytical methods during the past years has enabled the detection of active drugs in our environment. The occurrence of drugs in our aquatic systems is today a well accepted fact. The source of this pollution is in Sweden probably mainly normal drug consumption and an inability of the waste water treatment plants to remove these compounds. In other parts of the world where there are less strict regulations, also the pharmaceutical industry significantly contributes to high concentrations of active compounds in the environment. Drugs are constructed to have an effect on biological systems at low concentrations. It is therefore problematic with pollutions that can affect ecosystems and there exert toxic effects. A classic example is the description of vultures in India that have died from intoxication of diclofenac acquired from feed. Furthermore, pollutions of antibiotics may affect the development of bacterial resistance.
It is of utmost importance to develop sensitive and selective analytical methods to detect and quantify active drugs in different parts of our environment in order to enable eco-toxicological evaluations. Degradation products of the active compounds can sometimes be more potent than the parent compounds or even toxic. It is therefore important to be able to identify which products that are formed naturally in the environment and in different types of waste water treatment procedures involving biological or chemical processes.
The technique mainly used for identification as well as quantification of drugs in environmental samples is UHPLC-MS(/MS) with electrospray ionization. Also supercritical fluid chromatography SFC-MS(/MS) is used in our research group. The chemical complexity of the sample materials from e.g. waste water is a great challenge in the analysis. There is a great risk if matrix effects that may interfere with the mass spectrometric signal of the analytes and thereby affect the possibility to make accurate measurements.
In our group, the degradation of drug substances in different aquatic systems is studied. For chiral compounds, the enantioselectivity in the degradations processes are studied in order to conclude whether biological systems (enzymes) are involved. The degradation products formed are identified with high resolution mass spectrometry (Q-ToF MS).