Sample Preparation


Sample Submission

UC Davis Plant Sciences

Carbon Dioxide (CO2) Sample Preparation

CO2 gas samples should be sent in septum-capped vials preferably at atmospheric pressure (~100 kpa), but pressures up to 200 kpa are acceptable. Optimal CO2 gas concentration range is ambient to 20,000 ppm, with a maximum of 50,000 ppm; higher concentrations can be subsampled for a fee.


Gas concentration data (ppm) are required for each sample. 


Sample vials are 12 mL Exetainers (Labco Ltd, High Wycombe, UK), but others may be acceptable with prior arrangement. Please note, the wide (###W/W) 12 mL Exetainers supplied by Labco do not fit our autosampler trays and should not be used (see supplies table below). Sample containers should be evacuated prior to sample collection. The caps should be finger-tight; do not over-tighten the caps as the septa will pucker and potentially compromise the seal.


We do not accept gas samples collected in BD Vacutainers with press-fit caps.


Label each vial with a unique Sample ID#, and record the sample details on a Sample List; your data will be reported using the Sample ID. An estimate of the CO2 gas concentration in your samples will help us prepare laboratory reference materials in the appropriate range.


To ensure the best possible analysis, test samples should accompany 13C-enriched samples when the maximum level of 13C-enrichment is unknown or cannot be estimated. Questions? Contact Rick Doucett


Manufacturer / Part#



Labco UK + International

or Labco USA + Canada

839W, 739W

Exetainers: 12mL Soda Glass Vials,

flat bottomed, labeled, white cap,

evacuated (839W) or non-evacuated (739W)*

Case of 1000

EA Consumables / E2852


12ml Soda Glass Vial Flat bottom-739W- 101x15.5mm Non-Evacuated labelled Seal + White Cap

Pack of 1000

EA Consumables / D2852-100


12ml Soda Glass Vial Flat bottom-739W- 101x15.5mm Non-Evacuated labelled Seal + White Cap

Pack of 100

EA Consumables /

E2885 (Labco#VC309)

E2886 (Labco#VC306)

E2887 (Labco#VC303)

E2866 (Labco#VC301)

Pierceable Cap & Septa:

White VC309

Orange VC306

Grey VC303

Blue VC301

Pack of 1000

Microliter Analytical/ 20-2000-S

Clear Vials with Beveled Top, Silanized

23x75mm, 20mL

Pack of 100

Microliter Analytical/ 20-0025-B

Septa, 20mm Gray Butyl Stopper  

Pack of 1000

Microliter Analytical/ 20-0000AS-B

Seal, 20 mm Standard Aluminum 

Pack of 1000

*Note: Labco has a wider vial style that ends in ###W/W.  We DO NOT accept these vials at the SIF because the vials are too wide for our autosampler racks.  

e-mail: | phone: 530-752-8100 | fax: 530-752-4361
UC Davis Stable Isotope Facility | Department of Plant Sciences
One Shields Avenue | Davis, California, 95616 | USA