Radiochronology laboratory

 

 

Great results for the Radiochronology Lab at the 14C community inter-comparisons (SIRI) !

 

Forms quick links

 

Laboratory description

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 and carbonates.  We now offer the dating of bone samples.

The Pb-210 and Cs-137 datation service is also offered for sediments.

C-H-N analyses 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

AMS dating is possible on very small samples (a few milligrams). CEN has the equipment and expertise to prepare samples for AMS dating, which includes 2 major steps:

  • Sample preparation by fractionation of their carbon components followed by oxidation and reduction to graphite. The graphite produced is pressed into a target for AMS measurement. Chemical processes are involved in this step.
  • The counting in a particle accelerator, which involves specialized nuclear physics.

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.

It is this CO2 tube that will be shipped to an external laboratory that has an accelerator mass spectrometry facility. This laboratory will convert the CO2 into graphite, and this graphite will be counted in the accelerator.

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.

Pb-210 and Cs-137 dating

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).

CHN Analyses

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.

Submitting samples

14C dating

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 fill the AMS dating form  (PDF)   (Word)  for each sample submitted. Join the form(s) with your package of samples.

Pb-210 & Cs-137 counting

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).

Please fill the Pb-210 dating form   (PDF)   (Word)  for each core (not for each sample) submitted for analysis. Join it with your batch of samples from your core.

C-H-N Analyses

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:

RADIOCHRONOLOGY LABORATORY
c/o Guillaume Labrecque
Laval University
Abitibi-Price Building, Room 0248
2405, Rue de la Terrasse
Quebec, QC CANADA
G1V 0A6

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.

Price list as of June 1st, 2017 ($ CAN)

 

  Sample Size (dry weights) Cost ($ CAN)
  Minimum Best University
Educational
Others
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     30.00 30.00
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
 
 
  Minimum Best CEN members
Université Laval
Others
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.
 
Notes
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).

 

Billing and payment

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

Room 0248
Abitibi-Price Building
Université Laval
2405 rue de la Terrasse
Québec, Canada
G1V 0A6

radiocarbon@cen.ulaval.ca

Phone : (418) 656-2131 ext. 4486