Source: TDA RESEARCH, INC. submitted to NRP
PORTABLE NON-OPTICAL MEASUREMENT OF PHOSPHOROUS IN MARINE ENVIRONMENTS TO INFORM MANAGEMENT AND CONSERVATION AT THE WATERSHED SCALE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
SMALL BUSINESS GRANT
Reporting Frequency
Annual
Accession No.
1031756
Grant No.
2024-33530-41786
Cumulative Award Amt.
$175,000.00
Proposal No.
2024-00037
Multistate No.
(N/A)
Project Start Date
Jul 1, 2024
Project End Date
Feb 28, 2025
Grant Year
2024
Program Code
[8.4]- Air, Water and Soils
Recipient Organization
TDA RESEARCH, INC.
12345 WEST 52ND AVENUE
WHEAT RIDGE,CO 80033
Performing Department
(N/A)
Non Technical Summary
Protecting the quality of water in the nation's streams, rivers, lakes, and estuaries is a critical need and important for human and ecosystem health.Efficient protection requires knowledge gained from real-time or near real time information on nutrient concentrations and loads. Thisinformation feeds into predictive models and informs policy decisions. In this project, we are creating a new tool to add to the arsenal of those protecting the nations water assets based on low-magnetic field nuclear magnetic resonance (NMR) spectroscopy.
Animal Health Component
40%
Research Effort Categories
Basic
20%
Applied
40%
Developmental
40%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
11102102000100%
Knowledge Area
111 - Conservation and Efficient Use of Water;

Subject Of Investigation
0210 - Water resources;

Field Of Science
2000 - Chemistry;
Goals / Objectives
Phosphorous (P) is one of the primary nutrients that plants require, but it can disrupt aquatic systems when its concentrations are too high. Excess P can cause eutrophication, resulting in fish kills, toxic algae, and degraded drinking water quality, especially in rural, agricultural areas. Careful monitoring of P levels is required to effectively manage human interactions with water sources, and to manage P runoff. Currently measuring P in water sources requires sample send out to a lab. The results turn around (3-4 weeks) is much longer than the timescale of P cycling in the ecosystem. Information to guide management related to fast occurring events (like storms) that can release more P from high runoff areas (like farms) is often missing. There is an immediate need for lab-quality data to be generated at the water source, at higher temporal resolution (i.e. faster times), to drive effective water management decisions, and inform agricultural best management practices. TDA proposes a novel method to monitor phosphorous (P) concentrations in surface waters, such as lakes and rivers, that is fast, inexpensive, and remotely deployable. This is in direct response to Topic 8.4: Conservation of Natural Resources, specifically the "water quality and quantity" research priority. This proposal also has a connection to "agriculturally related technology", a broader USDA SBIR program priority. USDA Strategic Objective 2.3 is to foster agricultural innovation. Monitoring is crucial for making data-informed decisions regarding farm-level practices to manage phosphorus, and continuous, remote monitoring is a major innovation.Technical ObjectivesWe will develop the 31P-NMR measurement for phosphorus in surface waters in a form factor which can be deployed for long term remote monitoring. We will demonstrate measurement success through controlled measurements of lake water samples, comparing with laboratory measurements of standard P solutions. We aim to prove that the 31P-NMR approach can detect the median urban water P concentration of 0.25 mg/L, or lower, and within 2 hours of averaging by the end of the Phase II. To accomplish these goals, we have laid out the following goals and objectives for our Phase I work:(Goal 1) Design & construct permanent magnet (B0) with sufficient magnetic field homogeneity.Obj. 1 - Simulate permanent magnetic design in COMSOL to achieve very high magnetic field homogeneityObj. 2 - Build permanent magnet prototpyeObj.3 - Measure homogeneity with high sensitivity magnetometers and compare to simulation. Iterate between simulation and design, if needed, to achieve mangetic field homogeneityObj. 4 - Demonstrate 1H-NMR and 31P-NMR using permanent magnet design as final test of sufficient field homogeneity(Goal 2) Upgrade our FPGA board for RF handling to execute hyperpolarization experiment.Obj. 1 - Start with currnet FPGA design for NMR only experiment, and plan out addiiton of RF excitation chainObj. 2 - Build and Test FPGA NMR + RF chain on test benchObj. 3 - Demonstrate FPGA ability to complete hyperpolarization experiment3. Perform head-to-head comparison between the 31P-NMR sonde and atomic emission analysis to show the in-situ technique provides comparable analysis to the laboratory method.Obj. 1 - Make up stock solutions of 31P containingsolutions at low and high concentrationsObj. 2 - Analyze stock solutions with in-house microwave-power atomic emission spectrometer (MP-AES) to quantitfy stock solution concentrationsObj. 3 - Measure stock solutions with 31P-NMR. Sub-objectives are measureing with NMR only and long averaging, or with NMR+Hyperpolarization to decrease measurement timeObj. 4 - Compare "gold standard" MP-AES data with 31P-NMR and assess LOD capabilities of 31P-NMR4. Demonstrate 31P-NMR function on lake water samplesObj. 1 - Collect lake water from nearby Evergreen Lake and analyze for 31P-NMR content in "natural" stateObj. 2 - Spike lake water with known concentrations of 31P-compounds and measure with 31P-NMR without any other sample prepObj. 3 - Take lake water samples and execute extensive preparation done for high-magnetic field 31P-NMR, including removing Fe and Mn ions, and bringing up to pH 12. Run samples and compare to literature examples of 31P-NMR at high magnetic field.
Project Methods
Mobile, low-magnetic field-NMR is built around the idea of the "on-site" sensor or probe. In traditional NMR, a very small amount of sample is brought to the laboratory spectrometer. In mobile-NMR, the sensor comes to the sample. As such the sample size which is interrogated can be greatly increased. The analysis of much larger sample sizes in mobile-NMR applications offsets the loss in signal intensity from operating at lower magnetic fields. For existing high-magnetic field analysis, sample sizes used are 1 cm x 4 cm (V ~ 3 mL). The limiting factor is the difficulty in maintaining a high magnetic field homogeneity over a large space. The signal amplitude which can be observed is directly related to the concentration of spins (magnetically active nuclei), the volume of spins, and the applied magnetic field. If the volume of spins is limited by small sample size, the easiest way to increase signal amplitude is to increase the magnetic field strength. Thishas been the default approach for NMR for the past 70 years. However, when performing NMR in low-magnetic fields, one is not limited by sample volume, and some of the decreased signal amplitude lost by decreasing magnetic field strength can be regained by using a larger sample.The project will be accomplished through use of a well synchronized highly skilled team. The team leader, Dr.Biller, has 14 years of experience in designing, buidling, and validating low-magnetic field paramagnetic and nuclear magnetic resoannce hardware. Dr. Kevin Finch is an Analytical Chemist with a background in elemental analysis and will help set the "gold-standard" 31P measurements used to validate the new 31P-NMR technology. Mr. David Long holds dual degrees in Electrical and Mechancial Engineering, an associates degree in Precision Machining, and is currently completing his MS in Electrical Engineering on top of a full work week. In additon, Mr. Long has prior experience deisgning and building permanent magnets. Mr. Cory Van Beek is an electrical engineer who logged more than 42,000 lines of FPGA code at GE Healthcare prior to coming to TDA Research. Dr. Adrienne Delluva is a skilled materials scientist with a background in thin polymer films which will suppor the hyperpolarization film for signal amplification. Finally, Mr. Bradley Spatafore is a Sr. Mechanical Engineer who specializes in porting in-lab scientific measurements into the "real-world". Mr. Spatafore has worked with Dr. Biller in other projects to produce a consumer ready portable technology.Progress meetings are held weekly to identify problems early so we keep the project moving forward. Every new design is tested with stepwise measurement and components are validated independently from one another. For instance, we do not simply build a permanent magnet we "think" will work and attempt to measure NMR. We will model a design in COMSOL software which produces a field amplitude and homogeneity over a working volume we can confirm by using our exisitng library of high-sensitivity magnetometer devices. Once we've indpendently measured sufficient field homogenetiy, we will validate it can produce NMR using our well characterized existing benchtop NMR system (built by Dr. Biller). At the same time, the FPGA-NMR and RF-signal amplification chain can be independently validated by an existing benchtop electromagnet to ensure all experiment parameters are executed correctly. After the in-field permanent magnet and the in-field electronics are separately validated, they are combined to form the heart of an in-field NMR spectrometer.From here we can quickly bench mark the limit of detection of our new in-field NMR technique by comparison with gold-standard elemental analysis with MP-AES. We do this comparison not just with laboratory grade water samples spiked with phosphorus, but with lake water samples spiked with phosphorus and with lake water samples prepared for phosphorus analysis under high magnetic field NMR conditions.The three main metrics of success in the Phase I will be 1.) a compact permanent magnetic field design for in-situ large volume sample analysis 2.) A robust set of miniaturized electronics to run the experiment with high fidelity and acquire and process raw data into a NMR spectrum and 3.) the brand new knowledge of the trade offs between sample size, magnetic field strength and signal amplication for 31P-NMR in clean (lab water) and dirty (lake water) matrixes.Completion of the 3 main metrics set the state for aPhase II programto transition the Phase I work into a new commercial tool by the end of the two year Phase II time frame.

Progress 07/01/24 to 02/28/25

Outputs
Target Audience: Our previous customer discovery work, and feedback during the Phase I SBIR project, emphasizes the commercial need for this product. With Phase II development, TDA's measurement system could provide near-immediate measurements of phosphorous (P) levels in any water source. This is important data for all researchers and management agencies that deal with water quality and informs efforts to restore and protect. Water resources are crucial for balanced ecosystems and human activity including drinking, agriculture, and recreation. All such industries can benefit significantly as conserving the quality of water also conserves the quality of the activities that depend on it. Regulatory forces are also a driving factor towards commercial interest in improved P monitoring and help to define the target audience for the device. The predominant force for water quality monitoring, including nutrients like phosphorus, is the Clean Water Act, established in 1972, which is the primary federal law governing water pollution. Its objective is to monitor and restore the chemical, physical and biological integrity of the nation's waters. Beyond this, the U.S. Environmental Protection Agency (EPA) has encouraged states to adopt Total Nitrogen and Total Phosphorus Numeric Water Quality Standards. These numeric criteria help identify and list impaired waters, develop Total Maximum Daily Loads (TMDLs) and write National Pollutant Discharge Elimination System (NPDES) permits for wastewater treatment plants (WWTPs) discharging nitrogen and phosphorus. Overall, TDA's 31P-NMR sonde has the potential to have a positive impact for the conservation of water on a broad scale. These regulations and water monitoring criteria helped shape the target audience for this technology. During the Phase I project we targeted development of our 31P-NMR sonde to be compatible with companies that already manufacture various sondes for monitoring nutrients. The Aquatroll and the Exo3 are manufactured by In-Situ and YSI, respectively. Both of these sonde's are capable of measuring nitrate, so the sonde developed by TDA to measure phosphate would give additional capabilities to either company. The Cycle-PO4 is manufactured by Sea-Bird scientific and uses microscale colorimetric (Molybdenum blue) measurement of phosphate in a sonde. The 31P-NMR sonde accounts for deficiencies which are unavoidable in the colorimetric approach and could allow Sea-Bird to offer phosphate monitoring sondes to a wider customer base. Major players in the overall water-quality monitoring market are Danaher Corporation, Evoqua Water Technologies, General Electric Company, Horiba, Ltd., OAKTON Instruments, Pentair, Shimadzu Corporation, Thermo Fisher Scientific, Inc., Uponor, and Xylem Inc. The 31P-NMR sonde developed by TDA would be an entry point for these companies into the market for unmanned, remote, near-continuous monitoring of phosphates. TDA would finish development of the prototype instrument in-house during a Phase II project and license the novel technology to one of these companies who has dedicated marketing and sales teams for water quality monitoring system. TDA has the full capability to manufacture multiple 31P-NMR sonde units for initial demonstration and sale while licensing negotiations are being held. Changes/Problems: Task 6: Phosphorous (P) levels in real water sources can vary widely. Pristine lakes can have values lower than 0.01 mg/L, while wastewater effluent has an EPA defined limit of 0.5 mg/L or 1 mg/L depending on the source. Generally, the EPA recommends total P limits of 0.05 mg/L for streams that enter lakes, and 0.1 mg/L for flowing waters to prevent eutrophication ?(Litke, 2000)?. Considering these values, TDA needs to drop the LOD on our technique to below 1 ppm before measuring environmental water samples. Our measurement system currently has high noise levels preventing low LOD values. Water was collected from Clear Creek in Golden, CO; however, it was not measured due to this LOD issue. Spiked creek water samples with known phosphorus-containing compounds (like the previously measured phosphoric acid or penta-sodium triphosphate) were also not measured, because the matrix effects were anticipated to be too subtle to measure with the system in its current state. Natural freshwater has other dissolved metals such as iron and manganese which are paramagnetic and can broaden the measurement spectrum collected by NMR. These effects can be small at low field strengths, and we hypothesized that we wouldn't be able to resolve the spectrum differences pick them up with the high LOD values achieved. Despite this, there are many identified opportunities to improve the SNR of our low-field P NMR measurement. The first few are device-level changes: (1) we can take more averages which increases the SNR in proportion to the square root of the number of measurements. (2) we can improve the electrical shielding in our prototype to reduce noise and (3) we can increase the magnetic field of the permanent magnet up to about 500 mT as the practical limit. Finally, we can implement more advanced NMR techniques to increase the signal such as dynamic nuclear polarization (DNP), which we have already begun looking into. Overall, this task was unable to be completed because the SNR of the measurement needs to be improved before testing samples which use natural water. Improving the measurement SNR and bringing down the LOD are the current research priorities for this work and many feasible strategies to do so have been identified that could be implemented during a Phase II. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?During a Phase II award, TDA would work on improving the measurement SNR and bringing down the LOD of the 31P measurement. These are the current research priorities for this work and many feasible strategies to do so have been identified. The first few are device-level changes: (1) we can take more averages which increases the SNR in proportion to the square root of the number of measurements. (2) we can improve the electrical shielding in our prototype to reduce noise and (3) we can increase the magnetic field of the permanent magnet up to about 500 mT as the practical limit. Finally, we can implement more advanced NMR techniques to increase the signal such as dynamic nuclear polarization (DNP), which we have already begun looking into.

Impacts
What was accomplished under these goals? (Goal 1) Design & construct permanent magnet (B0) with sufficient magnetic field homogeneity. Obj. 1 - Simulated high homogeneity permanent magnetic design in COMSOL Obj. 2 - Built permanent magnet prototype after iterating through multiple designs. Obj. 3 - Achieved magnetic field homogeneity needed for both 1H-NMR and 31P-NMR Obj. 4 - Demonstrated 1H-NMR and 31P-NMR using TDA's permanent magnet design (Goal 2) Upgrade our FPGA board for RF handling to execute hyperpolarization experiment. Obj. 1 - Removed complicated FPGA board and used better alternative (Digilent Analog Discovery ADP3250) Obj. 2 - Programmed Digilent to perform single-pulse NMR experiments Obj. 3 - Demonstrated ability of Digilent ADP3250 to measure 1H-NMR and 31P-NMR (Goal 3) Perform head-to-head comparison between the 31P-NMR sonde and atomic emission analysis to show the in-situ technique provides comparable analysis to the laboratory method Obj. 1 - Produced stock solutions of 31P at low and high concentrations with both H2O and D2O as diluent Obj. 2 - Found out the detection limit is too high to measure Phosphorous on the MPAES and used sotkc solution concentrations as the known concentrations Obj. 4 - Measured the LOD of 1H-NMR (5,600 ppm) and 31P-NMR (12,780 ppm) using the Digilent NMR and the 73 mT Permanent Magnet System (Goal 4) Demonstrate31P-NMRfunctiononlakewater Obj. 1 - The current S/N was found to be too low to detect natural sources of 31P and needed improvements to the measurement were identified (Hyperpolarization, Longer Averaging, Improve Electrical Shielding, Use a Higher Magnetic Field)

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