Breadcrumbs

Quality Assurance

The Waikato Radiocarbon Dating laboratory led an international 5-lab 14C inter-comparison, which represents a benchmark for determining accuracy and reproducibility. The 5 labs analysed 12 successive decadal kauri samples ~10,000 14C years in age with the high resolution sampling providing laboratory offset information previously unavailable in other inter-comparisons.


This type of quality assurance (QA) programme is a far more effective measure of 14C QA than any ISO quality accreditation. The Waikato Radiocarbon Dating laboratory results (both radiometric and AMS) were found to be highly consistent with the other labs. The radiocarbon community has since recognised the excellence of this research and some of the samples will be utilised in the next International Radiocarbon Inter-comparison exercise. The results are published in Radiocarbon with the paper free to download (Hogg et al 2013b).

Inter-comparison results for 12 successive ~10ka kauri samples—final results.

Quality Assurance

Inter-comparison results for 12 successive ~10ka kauri samples—final results. (OxA = University of Oxford; ETHZ = Laboratory of Ion Beam Physics; Wk = University of Waikato-conven; Waikato-AMS; HD = University of Heidelberg; UCI = University of California at Irvine).

To measure laboratory reproducibility and crosscheck our results, we are also involved in inter-calibration exercises with the radiocarbon community. We have participated in all of the Glasgow University programs (including the recent 6th international radiocarbon inter-comparison) and the earlier International Atomic Energy Agency (IAEA) inter-comparison exercise. Assoc. Prof. Alan Hogg was also a member of the international advisory committee for the Fourth inter-comparison. Results of the 5th inter-comparison (VIRI) are given in the table below and show a high level of agreement between the Waikato Radiocarbon Dating lab determinations and VIRI consensus values.

Results of the Fifth International radiocarbon Inter-comparison (VIRI; 2007-2010) showing consensus values vs. University of Waikato results.


University of Waikato Results*


VIRI Sample- Standard Radiometric- AMSVIRI consensus values

Sample A (barley mash)

109.2 ± 04 yr BP

109.5 ± 0.53 yr BP

109.1 ± 0.4 pMC

Sample B (seed charred)

2855 ± 32 yr BP

2802 ± 33 yr BP

2820 ± 3.3 yr BP

Sample C (barley mash)

111.0 ± 0.4 pMC

111.02 ± 0.42 pMC

110.7 ± 0.04 pMC

Sample D (seed charred)

2842 ± 33 yr BP

2804 ± 32 yr BP

2836 ± 3.3 yr BP

Sample E (mammoth bone)

38347 ± 511 yr BP

40,809 ± 2239 yr BP

39,305 ± 121 yr BP

Sample F (horse bone)

2545 ± 30 yr BP

2477 ± 37 yr BP

2513 ± 5 yr BP

Sample G (human bone)

-

1035 ± 32 yr BP

969 ± 5 yr BP

Sample H (whale bone)

9491 ± 45 yr BP

9617 ± 49 yr BP

9528 ± 7 yr BP

Sample I (whale bone)

8360 ± 37 yr BP

8318 ± 43 yr BP

8331 ± 6 yr BP

Sample J (humic acid)

-

41,795 ± 1860

43226 ± 140 yr BP

Sample K (wood)

0.04 ± 0.04 pMC

0.09 ± 0.1 pMC

0.058  ± 0.06 pMC

Sample L (wood)

2269 ± 26 yr BP

2241 ± 30 yr BP

2234 ± 5 yr BP

Sample M (wood)

-

2442 ± 30 yr BP

2430 ± 4 yr BP

Sample N (cellulose)

-

2417 ± 36 yr BP

2436 ± 5 yr BP

Sample O (cellulose)

99  ± 25 yr BP

75 ± 30 yr BP

125 ± 5 yr BP

Sample P (charcoal)

1751 ± 27 yr BP

-

1747 ± 9 yr BP

Sample Q (charcoal)

-

600 ± 30 yr BP

636 ± 5 yr BP

Sample R (shell)

2469 ± 26 yr BP

2419 ± 30 yr BP

2491 ± 4 yr BP

Sample S (barley mash)

110.46 ± 0.36 pMC

110.2 ± 0.4 pMC

109.96 ± 0.04 pMC

Sample T (humic acid)

-

3335 ± 30 yr BP

3360 ± 4 yr BP

Sample U (humic acid)11829  ± 41 yr BP11746 ± 87 yr BP11778 ± 6 yr BP