Real-Time Mapping of Hydroxylamine and Other Trace Gases in Soil

Real-Time Mapping of Hydroxylamine and Other Trace Gases in SoilPI: Joseph Roscioli Aerodyne Research Inc.Project SummaryThe nitrogen cycle is fundamentally important to ecosystem health crop productivity foodsecurity biosphere-atmosphere exchange air quality and climate change.The processes thatdrive nitrogen transformations in soil are influenced by environmental conditions that can exhibitlarge variability leading to spatial and temporal heterogeneity of nitrogen cycling on millimeterand hour scales.These fluctuations impact nutrient availability for roots and the nearbymicrobiome that affect ecosystem health and plant productivity.These same variations can leadto hot spots and moments of intense gas production impacting air quality and climate change.Thecurrent state of knowledge of the nitrogen cycle is limited by a lack of empirical data atspatiotemporal scales necessary to challenge biogeochemical models.Improving thisunderstanding will better inform ecological and agricultural decision-making aimed at preservingnatural resources battling climate change and increasing crop productivity thereby helpingUSDA achieve its Strategic Goals 1 and 2.Aerodyne Research proposes to develop demonstrate and commercialize a novelsampling and detection system that can quantify subsurface concentrations or fluxes of keyintermediates of the nitrogen cycle - nitrate nitrite and hydroxylamine - on mm-scales andwith hourly time resolution.Current methods aimed at measuring these compounds are labor- intensive destructive insensitive or lack the necessary spatiotemporal resolution.The proposedsystem will couple soil solute extraction via microdialysis probes to the sensitive and selectiveAerodyne TILDAS infrared spectroscopic detection platform.It will be automated to interfacewith multiple probes enabling real-time subsurface mapping of these compounds.This capabilitystrongly complements existing Aerodyne products including subsurface gas sampling systems andtrace gas flux platforms. The proposed project will directly address the USDA research priority todevelop new technologies for measuring "soil nutrient content" and "microbial functional activityrelated to nutrient cycling" (SBIR Topic 8.4).The Phase II project builds upon a successful Phase I effort.During Phase I Aerodynedemonstrated the ability to quantify nitrate nitrite and hydroxylamine with micromolar sensitivityand high selectivity with the potential to achieve nanomolar sensitivity in Phase II.In Phase IIAerodyne will i) improve the interface between the microliter-scale microdialysis liquid and theTILDAS ii) develop a flow design and automated sampler to multiplex up to 16 probes iii) buildthe Phase II sampling system coupled to a TILDAS iv) refine the sampling and detectionmethodology and v) demonstrate the system in a real-world measurement scenario incollaboration with the University of California Riverside (Prof. Peter Homyak).An automated multiplexed system that maps key intermediates of the nitrogen cycle inreal-time will provide new and unique capabilities with significant commercial potential.Thecommercialized product consisting of the probes multiplexing extraction module and TILDASplatform will be marketed to the academic governmental and industrial soil research community;however it also has potential applications in other fields such as soil and water pollutionmonitoring downstream of agricultural areas and in ecologically sensitive regions.