The Influence of Matrix Effects on Trace Analysis of Pharmaceutical Residues in Aqueous Environmental Samples

Abstract

Pharmaceuticals are a class of emerging environmental contaminants. They are manufactured to be biologically active and to be persistent against biodegradation. This makes them more risky for the environment, as they can have negative impact on living organisms. However, still there are many problems in reliable analysis of these compounds due to low amounts and complexity of the environmental samples. The technique widely used for this purpose is liquid chromatography coupled with tandem mass spectrometry. One of the main drawbacks of this technique is the change in ionization efficiency-phenomenon known as the matrix effect. Matrix effects heavily influence both qualitative and quantitative analyses. Therefore, it also has impact on the quality of the obtained results. Thus the main aim of the present study was to investigate the influence of six different aqueous environmental matrices on the solid-phase extraction efficiency and the final determination of twelve selected sulfonamides by LC-MS/MS technique. The obtained results showed that both were strongly affected by the matrix composition. The more complicated the matrix was, the greater influence was observed (matrix effects in tap water were in the range from 8.77 to -16.49 % and in wastewater influents from -63.67 to -97.43 %). Extraction efficiency of selected drugs decreased from 94.9 to 41.5 % for tap water samples to from 31.6 to 0 % for wastewater influents. Thus, it is of high significance to use an approach to correct effects caused by matrix components. The proper calculation of the real concentrations of pharmaceuticals in the environment is required for determining the consequent risk to living organisms. © Springer International Publishing Switzerland 2014.