Development of high performance liquid chromatography tandem mass spectrometry (HPLC – MS/MS) method for determination of different classes of pharmaceuticals in waste waters

The presence of pharmaceuticals in the environment has been a great concern among scientists in the last few decades. They have been classified as emerging contaminants and their presence should be investigated in the environment. There are many ways pharmaceuticals reach the environment but the most significant one is via wastewater treatment plants (WWTP), because some of the pharmaceuticals are not eliminated completely during the treatment. Majority of those end up in the water systems and can reach drinking water sources. Once present in the environment they can have negative effects on organisms and influence the equilibrium of ecosystems. Their possible impact on human health also cannot be neglected. This environmental issue is still present and there is a constant need to develop new analytical methods for the determination and quantification of pharmaceuticals in the environment. The aim of this study was to develop a method based on solid phase extraction (SPE) followed by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) for simultaneous analysis of 22 pharmaceuticals. The choice of analytes covered six different groups of pharmaceuticals: macrolides, fluoroquinolones, tetracyclines, sulfonamides, anthelmintics and anesthetics. After the MS parameters were optimized, the optimal chromatographic conditions were obtained using phenyl column. The result of sample preparation step optimization was sorbent Oasis HLB, 60 mg with acetonitrile as eluent. Environmental samples are very complex and the matrix can affect the efficiency of ionization process in the ESI. In this study different approaches to compensate matrix effects were investigated in order to obtain more accurate results. After the optimization the method was validated and applied to the analysis of real waste water samples.