Combining passive sampling and tandem mass spectrometry for the determination of pharmaceuticals and other emerging pollutants in drinking water

Passive sampling and liquid chromatography-tandem mass spectrometry can be profitably employed to detect emerging contaminants in waters at very low concentration levels. In this work, two types of Polar Organic Chemical Integrative Sampler (POCIS) were subjected to calibration at two different temperatures to calculate the sampling rates of eight emerging pollutants (five pharmaceuticals, two perfluorinated compounds and caffeine). Results obtained changing the temperature from + 5 to + 25 °C showed a limited influence on the sampling rate values for all the selected analytes. Preliminary evaluations on storage life-time of POCIS devices were also taken into account. After calibration, samplers were deployed in the inlet and the outlet of two drinking water treatment plants in Northwestern Italy, for two and four weeks; the extracts were then analyzed by means of LC-MS/MS in multiple reaction monitoring mode, which provided high sensitivity and allowed the detection of the selected compounds at the low ng L− 1level. Three analytes were measured in both treatment plants: the two perfluorinated compounds, in the range 2.93–13.42 ng L− 1, and caffeine, in the range 0.07–0.93 ng L− 1.