Development and validation of a gas chromatography-tandem mass spectrometry analytical method for the monitoring of ultra-traces of priority substances in surface waters

The 2013/39/EU Directive of the European Parliament provided a list of substances (organic and inorganic compounds); these so-called priority and dangerous priority substances affect the quality status of surface waters. Due to their high level of toxicity, these contaminants have legal limits in the order of μg/L and even some in the order of ng/L and pg/L. To this aim, an effective and sensitive analytical method for monitoring these contaminants was deemed necessary. In this experimental process, a highly effective workflow represented by a pre-analytical and an analytical phase was developed and validated. The pre-analytical phase comprises a liquid-liquid microextraction and a quick, easy, cheap, effective, rugged, and safe purification. The analytical part was performed by a very sensitive and robust multi-residual GC-MS/MS method without the need for derivatization. This method simultaneously identified and quantified most of these substances (represented by pesticides, chloroalkane hydrocarbons, and polycyclic aromatic hydrocarbons) at very low concentration levels while respecting the analytical concentration limits required by the European directive.