Oxygen (18O) and Hydrogen (2H) Water Sample Preparation and Organization
Collect and store waters in gas impermeable vial without any headspace bubbles. The recommended volume for water samples is 2-40mL in a tightly-capped glass vial or small exetainer. Please contact us about low-volume (<250 µL) samples. Samples should be kept refrigerated and in the dark for long-term storage. Additional preservation is not necessary. We do not accept samples preserved with mercuric chloride (HgCl2) or poisoned with sodium azide (NaN3).
Samples will be stored for 3 months post-analysis and then discarded. Please review your data within this window.
Organizing samplesIn order to use the correct reference waters, please group water samples into the following classes:
|
Group |
δ2H |
δ18O |
|
Natural Abundance |
< 60 ‰ |
< 6 ‰ |
|
Low Enrichment |
60 to 1690 ‰ (0.042 at%) |
6 to 263 ‰ (0.25 at%) |
|
High Enrichment |
> 1690 ‰ (>0.042 at%) |
> 263 ‰ (>0.25 at%) |
The SIF enrichment upper limit for a δ2H value is 16036.4 ‰ and for a δ18O value is 1963.7 ‰.
For tracer studies, estimates on isotope values are required and samples must be organized by increasing enrichment.
Saline samples must be clearly marked with an estimate of the salinity. Organize saline samples in order of increasing salinity. Units of ppt or mS/cm are preferred. Organize water samples in order of increasing conductivity.
Turbid water samples or water samples containing precipitate must be filtered prior to analysis. If the SIF determines a water sample requires filtering, a $7.50 fee will be charged per sample for this service.
If your water samples have a pH < 5 or > 9, please contact us in advance of shipping your samples.
Shipping
Carefully package racks of vials in ziplock bags, small boxes, or their original boxes. 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 break during shipping. If samples must be shipped with a refrigerant, be sure to insulate your samples from freezing, especially when using glass vessels. Avoid using dry ice as a refrigerant, as samples in direct contact with a refrigerant like dry ice will crack 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 the completion of a separate form for each type of analysis.