Sample Submission & Reporting

1. How to send samples
2. Documentation
3. Sample Types
4. Sample Sizes
5. Reporting Times
6. Payment
7. Sample Failure Policy

From this week, all radiocarbon dating results by GNS Science will be calibrated using the new IntCal20 calibration curves. We’re excited about this new dataset, which will help us date materials with even greater accuracy. Learn more here >>

1. How to send samples


Send dry samples, where possible. Bacterial activity in wet samples can affect the final 14C age. Use a low temperature oven which has never been used for radioisotope experiments. Cover samples with lightly perforated foil and heat at a temperature of at least 40°C till dry.

Use courier or registered post. Trackable courier despatch or registered post is recommended and samples are acknowledged on receipt by us. Couriers commonly used include DHL and Federal Express but also consider your postal services as they usually have fixed price postage Priority or Express Mail International tracked envelopes or boxes allowing up to some maximum weight.If courier firm insists on a value for the contents use $1.00.

Label package as: "Samples for destructive Scientific Analysis - no commercial value".

Send samples to:

Rafter Radiocarbon Laboratory
GNS Science
National Isotope Centre
30 Gracefield Road, Gracefield
Lower Hutt 5010
New Zealand

Contact phone number for courier packages: +64 4 570 4637

2. Documentation

Sample identification. All samples should be accompanied by the Sample Submission Form with sufficient documentation to identify each individual sample. This would include the nature of the sample material, full name and contact details of the submitter and where applicable additional information for the purposes of invoicing e.g.. Order numbers

Treatment history. Details of any prior treatment of the sample, such as cleaning, drying, treatment with solvents or preservatives, or any repair work should also be supplied. The relevant information can be supplied via our Sample Submission Form, or copy can be emailed or faxed to you on request.

MPI Import Permit IMPORTANT!! Samples sent from outside New Zealand must be accompanied by a copy of the Import Permit. Failure to do this may result in your samples being delayed on entry into New Zealand. Do not send your samples without the permit.

  • Inclusion of the Import Permit with the sample submission documentation inside the package and writing the permit number on the outside of the package is all that is required.

Please contact us for submission form and import permit.

Rafter email graphic

Other permits. Materials such as ivory or coral are covered by the CITES Agreement (Convention on International Trade in Endangered Species). New Zealand is a signatory to the agreement, and sample materials covered by CITES must show an exemption code on the packaging. We can supply you with the appropriate code on request to facilitate the importing of the samples to New Zealand, but you are responsible for arranging the necessary permit to export the sample from the country of origin.

3. Sample Types

Samples can be submitted as:

  • Original material for full laboratory processing. Our sample preparation laboratory is experienced in handling a wide range of materials. We can advise you on the suitability of particular types of materials for radiocarbon dating, and we will be happy to discuss with you the most suitable way of taking a sample and packaging it to send to our laboratory.
  • Pretreated samples ready for combustion. The Rafter radiocarbon laboratory accepts samples of organic materials that have been pretreated by other laboratories. When no further pretreatment is required we offer a lower price for pretreated samples which still require combustion, graphitisation, AMS measurement and data analysis. However we reserve the right to charge the full price if we determine that further pre-treatment is required to proceed successfully and the client must acknowledge that we are not responsible for any contamination introduced into the sample due to laboratory procedures outside our control. Clients should contact us in advance of sample submission, so we may review the planned sample preparation procedure for any possible sources of 14C contamination, confirm that the sample pretreatment procedure is sufficiently effective, and make recommendations on number and types of processing blanks to be included.
  • Clean CO2 gas sent in break-seal tubes. We can accept 6mm and 9mm outer diameter sealed pyrex or quartz tubes between 16 and 20cm in length. The preferred amount of CO2 is approximately 2mg of Carbon or 4mls of CO2 at STP. For alternate tube sizes up to 15mm outer diameter please contact us. Some ideas for packaging for shipping include placing wrapped tubes inside rigid plastic tubing e.g., polythene piping. Taping the tubes to bubble wrap at regular intervals and rolling into a cylinder is another option. This can then be placed into a solid cardboard mailing tube or a rigid cardboard box.
  • Graphite, ready for pressing into cathodes or already pressed in SNIC-MS cathodes for insertion into the AMS wheel. We can advise on the best way of sending the graphite or cathode. Generally, it is advisable to send some test samples first, to ensure that your graphite will give a satisfactory output in our ion source. Guidance on how to populate the 40 position SNICS wheel with unknowns, blanks and standards can be found here

4. Sample Sizes

Ideally, samples should yield 1mg of carbon after processing, and the corresponding amounts of sample material are typically as follows:

Material Amount Required
Bone 500 - 3000mg, (Depending on condition)
Charcoal 10 - 50 mg.
Peat 100 - 1000 mg (Depending on carbon content)
Sediments 1 - 3 g (Depending on carbon content)
Shell & forams 10 mg
Textile 15 mg
Wood, cellulose 50 - 300 mg

Peats and Sediments - The carbon content of peats and sediments can vary greatly. 90 mg of a peat which has a 10% organic carbon content would yield sufficient material for dating, while a sediment which is only 0.1% organic carbon might require almost 9 grams. If you are unsure of the carbon content of your sample, please contact the laboratory before submitting so we may discuss size and treatment procedures which vary depending on the fraction you wish to date.

The minimum quantity for our standard measurement is 0.2mg of graphite. Samples less than 0.2mg graphite are known as "small" samples. Down to 0.05mg of graphite may be measured, but the precision of the results will suffer as a consequence, the reporting time will be >12 weeks (up to 16 weeks) and the price will be greater (a 30% surcharge will apply, and extra charges for partial processing should samples be withdrawn). Please contact us for advice. We would contact you before completing processing should it become clear that the sample will realise <0.2mg graphite.

5. Reporting Times

Results are usually reported 12 weeks after receipt of samples (regular size samples requiring full processing) and include:

  • δ13C (see note at foot of Sample Processing page)
  • Conventional radiocarbon age, fraction modern (defined by Donahue et al. 1990, without a decay correction) and Δ14C (as defined by Stuiver and Polach 1977, with a decay correction). Note we only report Δ14C if a date of collection, or other date to apply the decay correction to, is provided, since otherwise it is a meaningless value.
  • We don't usually report pMC, as there is some confusion in the literature as to how pMC is calculated (see Glossary for how to calculate pMC)
  • Where applicable, calibrated ages based on published international calibration data sets

Reporting time may be longer if batches of more than ten samples are submitted or if the nature/size of the material is such that special processing/measuring methods are required.

The total error reported for radiocarbon ages includes counting statistics and instrumental error. For ages less than 10,000 years the error is typically ± 25 years or less (for regular size samples > 0.2mg graphite). A high precision premium charge service offering reduced error may be available. Please contact us for details. (Email address above).

6. Payment methods

Information on payment methods is available here to download for reference:

7. Sample Failure Policy

Please feel free to ask us about the suitability of the material for radiocarbon dating. Under certain circumstances when samples fail in the process we may seek recovery of partial or the full costs of the laboratory treatment up to the point of failure. The sample failure policy is here: