Sample Materials

Physical and chemical pretreatments vary depending on the type of material and the depositional environment from which it came. It is important to understand the nature of the material being dated as certain organic fractions are more appropriate than others, depending on the environment. Below is a list of commonly dated materials, the factors that should be taken into account when selecting material, and the pretreatment methods that the samples will undergo prior to radiocarbon dating.

Wood and Charcoal

The radiocarbon age of wood corresponds the year the ring grew. Therefore the most appropriate date will often be from either the outer tree rings or small twigs. Try to ship only dry wood and please remove the bark.

Charcoal samples should be picked out, floated, or sieved from any accompanying sediment. Prior to shipping, please dry charcoal samples for 12-24 hours at temperatures not greater than 70°C.

Please visually inspect your samples and remove any rootlets or other signs of physical contamination. Our chemical pretreatment methods will remove post-depositional carbonates as well as humic acids. Please consult with us prior to sending wood samples that have been treated with shellac, oil, glue, etc.


Lake sediments

In many lacustrine environments, macrofossils are the preferred organic fraction used for dating. Macrofossils include charcoal, wood, plant, bone, shell, and seeds – not rootlets. We recommend isolating macrofossils with tweezers or by sieving in distilled, deionized water. Identification should be made prior to shipping. Macrofossils (except shell) will undergo the standard AAA pretreatment.

Bulk sediment can contain carbon from more than one reservoir and occasionally this can lead to a freshwater reservoir effect, such as in hardwater regions or lakes where old carbon is washed in from the catchment during spring melt or floods. Having said that, bulk sediment is widely used for radiocarbon dating, especially in cases when macrofossils are unavailable. If using bulk sediment, be sure to remove rootlets. For bulk samples, some consultation may be needed to determine whether a simple acid wash, AAA method, or compound specific analysis is needed.



Peat can be analyzed as either selected macrofossils or as bulk material. If shipping macrofossils, we recommend they be rinsed in deionised, distilled or ultra-pure (Milli-Q) water to remove residual sediment. Bulk peat samples often contain a silty component and a vegetable component. Both can be dated separately or together. Please remove visible rootlets prior to shipping and do not ship in aluminum foil as it may degrade. Airtight Ziploc bags are recommended. Samples will undergo AAA treatment, unless specified otherwise.


Humic acid/humin

Researchers sometimes request to date the humic acid (alkali-soluble) and humin (alkali insoluble) fractions of bulk sediment or peat. The general theory is that humic acids percolate downward and make radiocarbon dates appear younger. However, this is not always the case so it is important to test this method first before pursuing numerous analyses.


Shell and other carbonates

Physical pre-treatment of shells involves removal of the outer layer of the shell with a hand drill as well as chalky or recrystallized areas to isolate aragonite only. Chemical pretreatment may include the dissolution of the outermost shell in dilute HCl. Very small or powdered samples will not undergo this stage of pretreatment. 

It is not advised to store powdered carbonates for long periods of time as the large surface area exposes the sample to contamination by atmospheric CO2. If powdering the sample is necessary for sampling by drilling or powdered specific areas, we recommend that this be completed under an inert gas (i.e. N2, AR, etc.). The powdered samples should be stored in small glass vials and shipped to the lab without delay.


Bone, Antler, Teeth, Ivory

For the analysis of bone samples, collagen is extracted. Always send clean and dry bone samples as damp samples may contain mould which can cause deterioration of the collagen. Avoid porous (cancellous tissue) or soft bones as these are aslo likely to be low in collagen.

For δ13C and δ15N, we submit the extracted collagen to our partner lab, the GG Hatch Stable Isotope Laboratory. Please indicate on the submision form if you would like stable isotope measurements.

For teeth the dentine is most reliable for dating as the enamel exchanges carbon with the environment. The tooth root (which is dentine) may have better collagen preservation if it was protected for some time in the bone. Dentine also has a high initial collagen content.


Waters (DIC / DOC)

The researcher must decide if they would like to analyze the dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), or both (DIOC). Sample volume will vary depending on the amount of carbon in your sample. Concentrations [ppmC] are required at the time of submission. Ideally, each sample should yield minimum 1mgC (2mgC is ideal); please sample accordingly.

At present, we can only process DOC from fresh waters only. Please contact us if you are considering submitting water samples with higher total dissolved solids or potential hydrocarbon contamination for DIC.

If concentrations [ppmC] or DIC13 are required, we refer our clients to our partner lab - the G.G. Hatch Stable Isotope Laboratory; a separate aliquot and submission form is required. For submission guidelines and pricing, please see their website:

We recommend that our clients sample in pre‐cleaned (10% HCl), pre‐baked (500 °C for 3 hours) round bottom borosilicate glass bottles, (ideally amber bottles for DOC, or clear bottles covered in Al foil), capped with a black open top screw cap with butyl septa (ordering information below). If storage time is anticipated to beshort before shipping and analysis, you may sample with dense laboratory plastic bottles (HDPE) bottles (i.e. Nalgene). Waters must be gently filtered using a 0.45μm filter (pp/nylon, pre-rinsed in distilled water) or a pre‐baked (500 °C for 3 hours) 0.7 μm glass fiber filter (GF/F), depending on the application. No stabilizer is required once the samples are filtered. Fill the bottle with as little head space as possible. Keep samples cool and away from light. You will need to order bottles and closures:

1) Bottle ordering information (33‐430 closure size):

Clear 1L ‐ Kimble chase #61100‐1000; Wheaton #W219420 (recommended if concentration is unknown)

Clear 500ml ‐ Kimble chase #61100‐500; Wheaton #219419

Clear 250ml ‐ Kimble chase #61100‐250; Wheaton #219417

Clear 125ml ‐ Kimble case #61100‐125; Wheaton #219415

Amber 1L ‐ Thermo scientific #149‐1000; VWR #89095‐164

2) Closures (must be ordered separately):

Wheaton ‐ Black Phenolic Screw cap, open top with grey butyl septa, 33‐430 cap size, #240680 (

*Please order early in case of backorder*