Project 3: Methods for Selective Extraction, Concentration and Detection of N-Nitrosamines

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PROJECT SUMMARY/ABSTRACT – PROJECT 3 N-nitrosamines include some of the most mutagenic chemicals known to humankind, and they are present at and near Superfund Sites, in drinking water, and in food and drugs. What is needed are new methods to detect N-nitrosamines in water that can be used to enable distributed sensing. A major limitation in informing risk of exposure is the fact that N-nitrosamine detection requires sophisticated laboratory equipment in centralized locations. These methods, although highly accurate, are expensive and require trained technical staff. The goal of this project is to create materials and methods that are sufficiently inexpensive to be performed routinely by individuals without the need for detailed technical training. Specific Aim 1 is to create and deploy porous absorptive polymer films and particles with recognition elements specific for N-nitrosamines. Recognition containing solid phase extraction materials can be used to concentrate N-nitrosamines from water. Under conditions where N-nitrosamines are detected, Project 3 then contributes to the identification of which N- nitrosamines are present, to be done via conventional centralized laboratory determinations (to be developed by Project 4). Knowing which N-nitrosamines are present will guide studies of biological impact to be done by Project 1 and Project 2. Specific Aim 2 is to create and apply a novel NDMA optical sensor that exploits NDMA fragmentation products. The solid phase extraction materials also serve as a platform for field-deployed sensing systems. The detection mechanisms make use of photolytic breakdown of N-nitrosamines that can be conducted in solution or directly in solid phase extraction materials. Reactive species generated by photolysis allow for detection by additional reactions to organic aromatic molecules that can be used to create new emissive species or highly colored materials. Additionally, reactive species generated photolytically can be used to create chemiluminescence. Specific Aim 3 is to create a field-deployable device effective for use by community members to perform Citizen Science. The new optical based sensing methods given will be evaluated for sensitivity, accuracy, resistance to interfering species, and the ability to be translated to methods appropriate for use by community members. Providing sensing methods will be facilitated by leveraging smartphone cameras as detectors. Smartphone methods can be used in both colorimetric and emissive detection methods. With support from the CEC, empowering communities to frequently detect N-nitrosamines in their environment and water supplies will help to create a more comprehensive understanding of risk and how seasons, weather, and human interventions impact the exposure risks. Trainees will drive the research and will be supported by the Research Experience and Training Coordination Core, and research translation will be fostered by the Administrative Core. Results on which N-nitrosamines are present will be combined by the Data Management and Analysis Core with new understanding of biological impact to contribute to our comprehension of risk for specific water samples.