Methane in (CH4) in Gas

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

Methane (CH4) Analysis by GasBench-Precon-IRMS Tips
 

tightcap1) If requesting both 2H and 13C in CH4, two separate vials are required as the isotopes are analyzed separately. If sending water samples for CH4, a minimum of 12 mL water is required for each isotope.

2) Avoid over-tightening vial caps. Vials will leak when caps are over-tightened, causing the septa to pucker and pull away from the vial. Turn caps until snug, but not so far that the septa start to pucker.

3) Do not apply silicone grease, adhesives, or sealant to the tops of the vials. These materials clog the autosampler needle. The process of removing these sealants increases the risk of losing your gas sample due to dislodged septum.

4) Gas vials should be free of particulate matter or slurries, as the particles will clog our autosampler needle.

 

Shipping
Carefully package groups of Exetainers in Ziplock bags, small boxes, or their original boxes with dividers. Then package these sets in a larger sturdy box with Styrofoam peanuts or bubble wrap. Make sure the samples are very secure, loose vials can shatter during shipping. These gas samples do not require refrigeration during shipping. Coolers will not be returned.

Please complete and submit the online Analysis Order Form and Sample List for your samples.  Also, be sure to include a printed copy with your samples. The SIF uses this form to track your samples and to contact you regarding receipt of samples, data, and invoicing. For mixed analysis requests, we require completing a separate form for each type of analysis.