Nitrate (NO3) in Water

The Stable Isotope Facility (SIF) will be closing, effective July 26, 2026.

June 3, 2026
An Update on the Plant Sciences Stable Isotope Facility

Dear Faculty, Staff, Students, and Supporters,
After a lengthy review process and careful consideration, we have made the difficult decision to sunset the Stable Isotope Facility (SIF) in its current form, effective July 26, 2026.

The Department of Plant Sciences continues to face hard decisions surrounding funding allocation given the campus-wide request to reduce budgets. Over the past several years SIF has been operating with a significant and growing deficit and, despite extensive efforts over the last several months to find a solution that would allow the facility to continue to provide services to the research community, we have not found a model that is financially sustainable.

I want to thank SIF’s staff for their excellent work and dedication these past 25 years, and everyone who has played a role in supporting this facility.

We are committed to doing our best to support the researchers who rely on the facility during this transition, and will be in touch with individual clients about details of specific plans for handling existing orders over the next several weeks.

Sincerely,
Daniel Potter
Professor and Chair, Department of Plant Sciences
University of California, Davis

Original Letter

Nitrate (NO3-) in Water Pricing
 

Analysis Turnaround Time (weeks)

2024 Price per Sample (US$)

2025 Price per Sample (US$)

15N or 18O Analysis of NO3- in water using Pseudomonas aureofaciens bacteria.

Samples prepared by the SIF*

 

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$44.00

$59.50

15N and 18O Analysis of NO3- in water using Pseudomonas aureofaciens bacteria.

Samples prepared by the SIF*

 

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$48.50

$65.50

High enrichment (>5 atom%), TDN and/or NH4

digests surcharge

 

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$8.00

$10.00

Samples requiring extensive handling by the SIF (e.g., filtering) will be charged incidental fees per sample. Samples with missing or inaccurate nitrate concentrations will be charged for reruns.

The SIF no longer accepts customer-prepared nitrate in water samples. Due to the nature of bacterial denitrification preparation and analysis, we cannot offer appropriate quality assurance unless we prepare the samples (and standards) ourselves.

Enriched samples / tracer experiments - please contact the SIF prior to your experiment.