The Stir Bar Sorptive Extraction technique (SBSE) using a 20 mm long stir bar coated with 127 μL of polydimethylsiloxane (PDMS) was investigated as an on-site enrichment tools for trapping odorous compounds in tap water because T&O events in drinking water are often fleeting and unpredictable phenomena. For analysis, SBSE is used in combination with the thermal desorption technique and gas chromatography-mass spectrometry (TD-GCMS).
Halophenol and haloanisol compounds were investigated over their stability on the stir bar after enrichment. Whatever the temperature, 4°C or room temperature, compounds were stable and gave the same response after the TD-GCMS analysis during 15 days of storage.
Based on these results, a concept of a portable enrichment lab was implemented and enabled us to solve different flavour episodes in France and Sweden. Once the enrichment was performed on-site, the stir bars were sent to our laboratory for investigation and quantitation of odorous compounds.
In two case studies, halophenols and haloanisols were found responsible for the musty taste of the water. In the third case study, more than 200 polycyclic aromatic hydrocarbons (PAHs) were identified as potential odorous compound which gave a chemical taste to the water.