Chemical trace analysis and understanding of odor deviations in drinking water in Ghent

During storage and distribution of drinking water, the quality is influenced by both microbiological and physical-chemical processes, which can lead, amongst others, to taste and odor (T&O) deviations. As these deviations give the consumer a negative quality and safety perception, it is important to measure these T&O compounds and get insights into their formation pathways to ensure tasteful tap water. The major challenge here is that these T&O compounds are numerous and at least partially unknown, and can be perceived already at very low concentrations, which makes their identification and quantification difficult. In this respect, a new analytical method was developed based on thermal desorption gas chromatography-mass spectrometry, proceeded by a concentration step using stir bar sorptive extraction. Different parameters such as extraction time, phase ratio, and desorption conditions were experimentally optimized. The final method was used to investigate odor deviations in drinking water collected in multiple student rooms in Ghent. Nineteen (19) locations with reported bad smelling/tasting tap water were sampled and analyzed. Chromatograms were screened for thirty-two (32) possible T&O compounds, and 9 (13) of them were quantified (identified). In addition, a link was found between the described odor character (musty) of some samples and the presence of 2,4,6-tribromoanisole (0.72 - 1.9 ng.L-1) at concentrations well above the odor threshold concentration (8 pg.L-1). This research contributes to the understanding of odor deviations in drinking water in Ghent

Headspace volatile organic compound profiling of pleural mesothelioma and lung cancer cell lines as translational bridge for breath research

IntroductionMalignant pleural mesothelioma (MPM) is a lethal cancer for which early-stage diagnosis remains a major challenge. Volatile organic compounds (VOCs) in breath proved to be potential biomarkers for MPM diagnosis, but translational studies are needed to elucidate which VOCs originate from the tumor itself and thus are specifically related to MPM cell metabolism. MethodsAn in vitro model was set-up to characterize the headspace VOC profiles of six MPM and two lung cancer cell lines using thermal desorption-gas chromatography-mass spectrometry. A comparative analysis was carried out to identify VOCs that could discriminate between MPM and lung cancer, as well as between the histological subtypes within MPM (epithelioid, sarcomatoid and biphasic). ResultsVOC profiles were identified capable of distinguishing MPM (subtypes) and lung cancer cells with high accuracy. Alkanes, aldehydes, ketones and alcohols represented many of the discriminating VOCs. Discrepancies with clinical findings were observed, supporting the need for studies examining breath and tumor cells of the same patients and studying metabolization and kinetics of in vitro discovered VOCs in a clinical setting. ConclusionWhile the relationship between in vitro and in vivo VOCs is yet to be established, both could complement each other in generating a clinically useful breath model for MPM

Pilot-scale drinking water distribution system to study water quality changes during transport

Abstract Drinking water (DW) quality can change during distribution, leading to taste and odor events and microbial regrowth. Pilot plants mimicking distribution networks are crucial for understanding these changes. We present a new pilot plant design, including piping material, sensors, and instrumentation. The three independent loops (100 m each) of the pilot exhibit identical behavior, allowing simultaneous testing of three conditions. Monitoring includes taste and odor compound formation, microorganism regrowth, and dissolved organic carbon changes. Real-time measurements enable continuous monitoring, and inner pipe biofilm sampling is feasible. The pilot’s modularity facilitates studying climate change effects, different piping materials, and source waters on DW quality in the distribution network