|Great results for the Radiochronology Lab at the 14C community inter-comparisons (SIRI) !|
Radiocarbon dating is based on the continuous decay of the radioactive isotope of carbon, 14C. Radiocarbon is incorporated into all living organisms in proportion to its concentration in the environment. When an organism dies, carbon is no longer incorporated into its tissues, but the radiocarbon present continues to decay at a known rate.
We are using the AMS method (Accelerator Mass Spectrometry). We can date organic samples (wood, charcoal, seeds, peat, sediments, plants, roots), shells (and carbonates) and also bones (and teeth, ivory, antler).
The Pb-210 and Cs-137 datation service is also offered for sediments.
C-H-Nanalyses are also available now (possibility to get the percentages of C (Carbon), H (Hydrogen) and N (Nitrogen) for dry samples. The analyses are processed with a Leco CHN628 elemental analyzer.
AMS dating is possible on very small samples (a few milligrams). CEN’s radiochronology laboratory has the equipment and expertise to prepare samples for AMS dating, which includes 2 major steps:
After the samples are received and labelled, we proceed with their chemical pre-treatments.
The next step is combustion, which produces carbon dioxyde (CO2).
CO2 is then purified into a vacuum system.
The resulting ultra-pure carbon dioxyde gas is sealed into a glass tube with a torch.
This ultra-pure CO2 is then graphitized with a semi-automated graphitization line controlled by a touch-screen monitor.
The resulting graphite will be pressed onto a target with a dedicated pneumatic press.
These targets containing the graphite will be shipped to an external laboratory that has an accelerator mass spectrometry facility.
For a small additional cost, the IRMS (Isotope Ratio Mass Spectrometry) measurement of the delta 13C of your samples can also be done.
With every shipment of many unknown-age samples we must add samples coming from oxalic acid transformation (which is the international standard reference material for all radiocarbon laboratories), inert samples to determine the background value (blanks) as well as known-age samples (secondary standards), coming from multi-laboratory calibration. This procedure assures a never-ending following of the quality, accuracy and precision of the results given to customers.
CEN radiochronology laboratory also offers Pb-210 dating. It is possible to count the following radionuclides: Pb-210, Cs-137, Am-241, Cd-109, Co- 57 as well as Ra-226 (which is the average of Pb-214 and Bi-214) in sediments using the HPGe method (High-Purity Germanium detector).
CEN acquired a LECO CHN628 elemental analyzer, to determine percentages of carbon (C), hydrogen (H) and nitrogen (N) in soil samples.
Samples must be dry. They must be crushed and uniformely homogenized. These steps (drying of the sample, crushing and homogenization) can be done by the customer, or by our people at the laboratory, which will make for a slightly higher price per sample.
Samples must be dried, clearly identified and packed in plastic (or glass vials), or enveloped in aluminium foil or plastic bags (Ziploc type). Avoid packaging the samples in paper or other organic material.
Please contact us to get the plastic vials used in our counter (the transfer of the samples and capping into these vials can also be done by us at the lab). The samples must be dried. Compact the samples as much as you can in the vial and, if possible, try to get a similar height of sample for every vial. Each sample must be weighed with a precision of 0.1 mg.
If you want us to transfer and cap the samples into the plastic vials, please make sure that the samples reach us dried and properly identified. The samples must be packed in plastic vials or plastic bags (Ziploc type).
Samples must be dry. They must be finely crushed and homogenized.
These steps (drying, crushing and homogenization) can be done by the customer himself, or by our people at the laboratory, for a little fee per sample. Plastic or glass vials are preferred over Ziploc-style bags.
Please fill the CHN analyses form (PDF) (Word) for each batch of samples you're submitting. Join the form with your samples.
The samples must be mailed out to this address:
c/o Guillaume Labrecque
Abitibi-Price Building, Room 0248
2405, Rue de la Terrasse
Quebec, QC CANADA
For the custom declaration, you can write "Samples for scientific analysis, with no commercial value".
You will be contacted via e-mail when your samples reach us at the laboratory.
|Sample Size (dry weights)||Cost ($ CAN)|
|14C AMS (Charcoal, wood, peat, organics)|
|Wood and charcoal (clean samples, no pre-treatment) *||1 mg||5 mg||300.00||410.00|
|Wood and charcoal||10 mg||50 mg||300.00||410.00|
|Peat, plants, seeds, roots||10 mg||50-100 mg||300.00||410.00|
|Bulk sediments (1% of carbon min.) **||1 g||2-3 g||300.00||410.00|
|Humic acid extraction (from inorganic sediments)||100 mg||500 mg||415.00||565.00|
|Delta 13C measurement by IRMS||40.00||40.00|
|Modern biobased content testing (ASTM D6866 method)||5 mg||20 mg||320.00||440.00|
|14C AMS (Bone, tooth, antler, ivory)|
|Collagen extraction (includes 13C and 15N measurements)||1 g||3-5 g||390.00||490.00|
|14C AMS (Shells, carbonates)|
|Standard procedure with acid leaching||20 mg||50-60 mg||265.00||370.00|
|No leaching (forams or very small samples)||10 mg||20 mg||265.00||370.00|
|14C AMS (Skin, parchment, leather, hide, textiles, other)|
|Please, contact us for these types of samples||30 mg||500-800 mg||300.00||410.00|
|C H N analyses|
|Dried samples ready to analyze||250 mg||500 mg||15.00||25.00|
|Humid samples (needing drying, crushing and homogenization)||Variable||Variable||20.00||35.00|
|210Pb & 137Cs analyses ***||1 g||5 g||30.00||70.00|
|* Chemical pre-treatments are very important and must be proceeded with when quantities are adequate. However, for customers who know their sampling sites are clean, skipping pre-treatments will give these very small samples a better chance to be dated.|
|** If carbon content is known from a previous analysis, please write it on the AMS form.|
|*** Contact us to get the plastic vials that are used for counting, so weighing and capping can be done by yourself. This can speed up the process, as the required 21-day sitting time (to reach secular equilibrium) can then begin as soon as you're done with the capping and go on during shipping. Otherwise, samples can be weighed and capped here at the lab (a fee can be asked for submission of a large number of samples). A precision of 0,0001 g is best. Report includes activities (Bq/g) for 210Pb, 226Ra, 137Cs and unsupported 210Pb.|
|A bigger quantity might be required for samples that are dirty, dusty, sandy or with a high fraction of sediments.|
|The form that applies to the analysis is required (one per sample for 14C AMS (PDF or Word), only one per core for 210Pb & 137Cs
( PDF or Word) and only one per batch for C H N (PDF or Word)).
|Discounts can be available for large batches of samples (14C AMS).|
Submitters from outside Laval University will receive a bill to the address they provided on the dating form after they get their results.
Submitters from Laval University must fill the internal service form, then send it to the unit from where the bill be paid. Your department administration will then send the PO number to us at the laboratory before we can proceed with the analyses.
Contact : Guillaume Labrecque
2405 rue de la Terrasse
Phone : (418) 656-2131 ext. 404486