Methodological challenges of multi-residue analysis of pharmaceuticals in environmental samples

In the last five years dozens of papers are published on the development, optimization and validation of analytical methodologies for the analysis of pharmaceuticals in aqueous and solid environmental samples, and several hundreds of papers reported on the application of those methods in monitoring studies or studies on the fate and behavior of pharmaceuticals in the environment and during water treatment. In spite of apparent maturity of methods and protocols for the monitoring of pharmaceuticals in the environment, methodological challenges are still numerous. This paper discusses the potential pitfalls in the quantitative multiresidue target analysis of pharmaceuticals in environmental samples, such as preservation of samples, stability of analytes in the sample and in standard solutions, possible losses of analytes due to sorption on the glassware and/or filter materials and matrix effects in MS detection. Recommendations how to avoid or at least minimize the errors and wrong interpretation of data are given.