New developments in the analysis of fragrances and earthy–musty compounds in water by solid-phase microextraction (metal alloy fibre) coupled with gas chromatography–(tandem) mass spectrometry

Fragrances are widespread aquatic contaminants due to their presence in many personal care products used daily in developed countries. Levels of galaxolide and tonalide are commonly found in surface waters, urban wastewaters and river sediments. On the other hand, earthy–musty compounds confer bad odour to drinking water at levels that challenge the analytical capabilities. The combined determination of earthy–musty compounds and fragrances in water would be a breakthrough to make the traditional organoleptic evaluation of the water quality stricter and safer for the analyst. Two approaches were attempted to improve the analytical capabilities: analyte pre-concentration with a newly developed PDMS-DVB solid-phase microextraction fibre on metal alloy core and sensitive detection by tandem mass spectrometry (MS/MS). The optimization of SPME parameters was carried out using a central composite design and desirability functions. The final optimum extraction conditions were: headspace extraction at 70 °C during 40 min adding 200 g L−1 of NaCl. The detection limits in tandem MS (0.02–20 ng L−1) were marginally lower compared to full scan except for geosmin and trichloroanisol which go down to 0.1 and 0.02 ng L−1, respectively. alysis of different water matrices revealed that fragrances and earthy–musty compounds were absent from ground- and drinking waters. Surface waters of river Leça contained levels of galaxolide around 250 ng L−1 in the 4 terminal sampling stations, which are downstream of WWTPs and polluted tributaries. Geosmine was ubiquitously distributed in natural waters similarly in rivers Leça and Douro at concentrations <7 ng L−1.