Quality Assurance

The SUERC Radiocarbon Laboratory has a complete manual of Quality Assurance procedures covering all aspects of the dating process, from receipt of samples through pre-treatment and sample preparation to age calculation and the reporting of results. The laboratory takes part in all international inter-calibration studies and SUERC/Glasgow University has been involved in the organisation of almost all major international studies held during the last 30 years.

Samples prepared by the lab are measured at the SUERC AMS Laboratory using either the National Electrostatic Corporation 5 MV tandem AMS or 250 kV single-stage AMS. In each batch measured, approximately 30% of samples are for Quality Assurance purposes.

In addition to a significant number of primary standards (Oxalic Acid II - SRM-4990C), background standards (interglacial wood, Marine Isotope Stage 7 bone and geological carbonate) and known age secondary standards are also synthesised to graphite and measured.

Table 1 below illustrates the consensus results for two known age samples used in international inter-comparisons alongside the average results from our routine analyses during 2022. Table 2 shows the average laboratory background measurement for the same period.

‌Further details of the laboratory methods and QA procedure can be found in Dunbar et al. (2016).

 

Table 1: Known age secondary standards

  Consensus value
(± 1σ)		SUERC mean value
(± 1σ) 2022
Barley MashTIRI sample A
(2003)		 116.35 ± 0.0084 pMC 116.60 ± 0.37 pMC a
Humic AcidSIRI sample N
(2015)		 3369 ± 4 years BP 3368 ± 24 years BP b
a Based on 205 measurements in 2022
b Based on 471 measurements in 2022

 

Table 2: Laboratory background values

  SUERC mean F14C value
(± 1σ) 2022
Heidelberg wood (organic, non-bone)
VIRI sample K (2009)		 0.0012 ± 0.0004 a
Icelandic doublespar (carbonate)
TIRI sample F (2003)		 0.0016 ± 0.0006 b
Background Bone 0.0029 ± 0.0023 c
a 230 measurements   b 10 measurements   c 52 measurements