BEGIN:VCALENDAR VERSION:2.0 PRODID:-//ZContent.net//ZapCalLib 1.0//EN CALSCALE:GREGORIAN METHOD:PUBLISH BEGIN:VEVENT SUMMARY:Non-targeted analysis: Environmental chemistry in the age of comput ational mass spectrometry LOCATION:Chemistry A101 TZID:America/Denver DTSTART:20190001T000000 UID:2026-05-27-06-38-49@natsci.colostate.edu DTSTAMP:20260527T063849 Description:About the Seminar:\n\nRecent advancements in high-resolution ma ss spectrometry (HRMS) and its application to the field of environmental c hemistry have for the first time made possible identification of emerging contaminants in complex environmental mixtures without a priori knowledge of contaminant identity or occurrence. Here\, I present a strategy and ser ies of novel analytical workflows based on liquid chromatography\, high re solution tandem mass spectrometry (MS/MS)\, and new chemoinformatics tools (e.g. data processing\, spectral library searching\, and in silico MS/MS prediction) for identification of emerging environmental contaminants in e cological and indoor environmental samples. In this approach\, high resolu tion (R>\;240\,000) accurate mass (mass error <\; 1 ppm) analyses of e nvironmental extracts are subjected to recursive peak assignment\, adduct grouping\, isotope pattern scoring\, and molecular formula assignment. Mol ecular candidates are then subjected to confirmation criteria for tentativ e structural identification using rule-based in silico fragmentation\, lib rary searching\, and comparisons to literature data.\n\nI will discuss app lication of these methods to assess fate and occurrence of emerging contam inants in several environmental systems relevant to ecological and human e xposure\, including:\n\n Assessment of polar organic contaminant occurren ce and fate in North Carolina drinking water sources. Our results revealed a complex mixture of natural and anthropogenic organic compounds in NC su rface waters\, with analytical signals detected for >\; 5\,000 discrete compounds\, and high-confidence tentative structural ID’s for >\; 300 of these. The tentatively identified compounds present at high relative in tensity included markers of wastewater (e.g. sucralose\, methylbenzotriazo les\, and pharmaceuticals)\, stormwater (e.g. benzothiazole and substitute d urea and guanidine vulcanization accelerants)\, and agrochemical input ( e.g. simazine\, atrazine\, and fungicides such as carbendazim).\n Elucida tion of chemical structures corresponding to novel halogenated azobenzene dyes in the indoor environment. We have tentatively identified >\; 30 di sperse dyes in house dust\, six of which were identified definitively in o ur extracts using authentic standards (representing 100% verification succ ess for proposed tentative structures for these candidates). Prominent com pounds identified in dust include the brominated dyes Disperse Blue 373\, Disperse Violet 93\, and Disperse Orange 61\, along with several chlorinat ed analogs of these structures. Together\, these compounds comprise the ma jor components of one of the most commonly applied black dyes used for col oring synthetic fabrics. Quantitative measurements indicated that these dy es were present in house dust samples at levels up to 10 µg/g. Apart from their known mutagenicity\, disperse azobenzene dyes are also implicated a s contact allergens\, thus their occurrence in the indoor environment is o f concern with regard to human exposure potential.\n\n \; 4:00 pm END:VEVENT END:VCALENDAR