Philip Naysmith

University of Glasgow | UofG · Scottish Universities Environmental Research Centre (SUERC)

The Scottish Universities Environmental Research Centre (SUERC) has analysed >100,000 individual graphite preparations with two accelerator mass spectrometers. Analysis quality is maintained by a programme of secondary-standards measurement, and annual assessment of the resulting large dataset can provide insight into subtle effects. The same analy...

Given the complexity of the radiocarbon dating process, the diversity of materials being dated, the continued technical developments, GIRI (the Glasgow international radiocarbon intercomparison) is the next development of the series of intercomparisons to support continuing quality assurance. GIRI has been designed to continue this programme and to...

The radiocarbon (14 C) calibration curve so far contains annually resolved data only for a short period of time. With accelerator mass spectrometry (AMS) matching the precision of decay counting, it is now possible to efficiently produce large datasets of annual resolution for calibration purposes using small amounts of wood. The radiocarbon interc...

Программа сопоставления данных лабораторий радиоуглеродного датирования проводится более 30 лет и со временем развивалась в соответствии с меняющимися технологиями. В этой небольшой статье основное вни- мание уделяется различным материалам, которые используются для процедуры сопоставления, и очень кратко рассматриваются некоторые из возникших пробл...

Radiocarbon ( ¹⁴ C) dating is routinely used, yet occasionally, issues still arise surrounding laboratory offsets, and unexpected and unexplained variability. Quality assurance and quality control have long been recognized as important in addressing the two issues of comparability (or bias, accuracy) and uncertainty or variability (or precision) of...

Over the past 30 years, the format of the radiocarbon ( ¹⁴ C) intercomparison studies has changed, however, the selection of sample types used in these studies has remained constant—namely, natural and routinely dated materials that could subsequently be used as in-house reference materials. One such material is peat which has been used 12 times, s...

Each of the laboratory intercomparisons (from ICS onwards) has included wood samples, many of them dendrochronologically dated. In the early years, as a result of the majority of laboratories being radiometric, these samples were typically blocks of 20–40 rings, but more recently (SIRI), they have been single ring samples. The sample ages have span...

Radiocarbon ( ¹⁴ C) wiggle-match dating is a technique with a substantial potential to improve the precision of dating timbers in situations where dendrochronology is not tenable. However, one of the key reasons why obtaining a dendrochronological determination might be difficult is the short-lived nature of timbers on a range of archaeological sit...

Bone is frequently dated in archaeological studies and, especially for very old bones (more than 40,000 years old), it is critical to have an accurate and precise measure of the material-specific background value and its associated uncertainty. The SUERC Radiocarbon Laboratory has obtained a mammoth bone as a background bone standard and an appropr...

Radiocarbon (14C) has been measured in single tree ring samples collected from the southwest of the Fukushima Dai-ichi Nuclear Power Plant. Our data indicate south-westwards dispersion of radiocarbon and the highest 14C activity observed so far in the local environment during the 2011 accident. The abnormally high 14C activity in the late wood of 2...

The SUERC Radiocarbon Laboratory employs a one-step “background subtraction” method when calculating ¹⁴ C ages. An interglacial wood (VIRI Sample K) is employed as the non-bone organic background standard, while a mammoth bone (LQH12) from Latton Quarry is used as the bone background standard. Results over several years demonstrate that the bone ba...

Radiocarbon measurement is a well-established, routinely used, yet complex series of inter-linked procedures. The degree of sample pre-treatment varies considerably depending on the material, the methods of processing pre-treated material vary across laboratories and the detection of ¹⁴C at low levels remains challenging. As in any complex measurem...

Radiocarbon ( ¹⁴ C) dating is used widely in many projects as a basis for the creation and testing of chronological constructs. ¹⁴ C measurements are by their nature complex and the degree of sample pretreatment varies considerably depending on the material. Within the United Kingdom and Europe, there are a number of well-established laboratories a...

Radiocarbon activities were measured in annual tree rings for the years 2009 to 2015 from Japanese cedar trees (Cryptomeria japonica) collected at six sites ranging from 2.5–38 km northwest and north of the Fukushima Dai-ichi nuclear power plant. The ¹⁴C specific activity varied from 280.4 Bq kg⁻¹ C in 2010 to 226.0 Bq kg⁻¹ C in 2015. The elevated...

A 50-year-old Japanese cedar (Cryptomeria japonica) from Okuma, ∼1 km southwest of the Fukushima Dai-ichi Nuclear Power Plant, was cored and each annual ring was analysed for (14)C. The (14)C specific activity values varied from 330.4 Bq kg(-1) C in the tree ring formed in 1971 to 231.2 Bq kg(-1) C in the 2014 ring. During the periods 1971-1976 and...

Japanese cedar leaves from Iwaki, Fukushima were analyzed for carbon, cesium and iodine isotopic compositions before and after the 2011 nuclear accident. The Δ14C values reflect ambient atmospheric 14C concentrations during the year the leaves were sampled/defoliated, and also previous year(s). The elevated 129I and 134,137Cs concentrations are att...

This paper describes all the major procedures adopted by the Scottish Universities Environmental Research Centre (SUERC) Radiocarbon Dating Laboratory. This includes sample pretreatment, graphite production, accelerator mass spectrometry (AMS) measurement, associated stable isotope measurements, data handling, and age calculations, but with the mai...

A 30-year-old Japanese cedar (Cryptomeria japonica), collected from Iwaki, Fukushima in 2014, was analyzed for the long-lived radionuclide (14)C. Values of Δ(14)C varied from 211.7‰ in 1984 to 16.9‰ in 2013. The temporal Δ(14)C variation can be described as an exponential decline, indistinguishable from the general Northern Hemisphere Zone 2 (NH Zo...

Radiocarbon laboratories undertake rigorous programmes of internal quality control (QC) and overall quality assurance (QA). In a laboratory "inter-comparison" samples of the same age are dated at different laboratories using a range of techniques and the results are then compared. The authors summarise the results of the fourth of these scientific...

(14)C analysis of flue gas by accelerator mass spectrometry (AMS) and liquid scintillation counting (LSC) were used to determine the biomass fraction of mixed waste at an operational energy-from-waste (EfW) plant. Results were converted to bioenergy (% total) using mathematical algorithms and assessed against existing industry methodologies which i...

The SUERC Radiocarbon Dating Laboratory has recently replaced its spreadsheet-based record keeping with a new database program, custom designed to help laboratory staff manage the high throughput of nearly 5000 cathodes in the past year. The system can accept data from a variety of sources in addition to manual entry; experimental results can be up...

The SUERC Radiocarbon Dating Laboratory has recently replaced its spreadsheet-based record keeping with a new database program, custom designed to help laboratory staff manage the high throughput of nearly 5000 cathodes in the past year. The system can accept data from a variety of sources in addition to manual entry; experimental results can be up...

It is becoming increasingly clear that in order to generate accurate radiocarbon dates for bone collagen samples it is important to determine a sample-specific background correction to account for the greater complexity and higher number of steps in the pretreatment chemistry of this material. To provide suitable samples for the 14C community, 7 bo...

Announcement: Radiocarbon Laboratory Quality Assurance Program (SIRI) - Volume 54 Issue 2 - Marian Scott, Gordon Cook, Phil Naysmith

Determination of the radiocarbon (14C) content of airborne particulate matter yields insight into the proportion of the carbonaceous material derived from fossil and contemporary carbon sources. Daily samples of PM2.5 were collected by high-volume sampler at an urban background site in Birmingham, UK, and the fraction of 14C in both the total carbo...

We describe improvements to the in situ cosmogenic C-14 extraction system at SUERC made since 2004 and present new in situ cosmogenic C-14 and Be-10 data testing whether depth-profiles of these nuclides can be used to determine amounts and timing of erosion on a soil formed on a Younger Dryas moraine in Scotland. The SUERC in situ C-14 extraction s...

Many of the Loch Tay crannogs were built in the Early Iron Age and so calibration of the radiocarbon ages pro-duces very broad calendar age ranges due to the well-documented Hallstatt plateau in the calibration curve. However, the large oak timbers that were used in the construction of some of the crannogs potentially provide a means of improving t...

In 2003, a National Electrostatics Corporation (NEC) 5MV tandem accelerator mass spectrometer was installed at SUERC, providing the radiocarbon laboratory with 14 C measurements to 4–5‰ repeatability. In 2007, a 250kV single-stage accelerator mass spectrometer (SSAMS) was added to provide additional 14 C capability and is now the preferred system f...

Proficiency testing is a widely used, international procedure common within the analytical chemistry community. A proficiency trial (which VIRI is) often follows a standard protocol, including analysis that is typically based on z-scores, with one key quantity, σ p . From a laboratory intercomparison (sometimes called a proficiency trial), we hope...

In this paper, we describe improvements to the in situ cosmogenic radiocarbon extraction system at SUERC made since 2004, highlighting the factors that potentially control the reduction of analytical variability. We also present new results on system blanks and of measurements of in situ 14C in shielded quartz and a surface quartz sample used at th...

We operate a new NEC 250kV single-stage accelerator mass spectrometer (SSAMS) next to our established 5MV tandem. This permits good comparison of 14C-AMS and challenges SSAMS performance. Initial SSAMS ion-optical deficiencies have been addressed by shimming the injection magnet and 3‰14C/13C measurement with background limited by sample chemistry...

The Fifth International Radiocarbon Intercomparison (VIRI) continues the tradition of the TIRI (third) and FIRI (fourth) (Scott 2003) intercomparisons and operates in addition to any within-laboratory quality assurance measures as an independent check on laboratory procedures. VIRI is a phased intercomparison; results for the first phase, which emp...

In 2003, a National Electrostatics Corporation (NEC) 5MV tandem accelerator mass spectrometer was installed at SUERC, providing the radiocarbon laboratory with 14 C measurements to 4–5‰ repeatability. In 2007, a 250kV single-stage accelerator mass spectrometer (SSAMS) was added to provide additional 14 C capability and is now the preferred system f...

The sustainable use of soils represents one of the key challenges that society faces. Glacial sediments (tills and moraines) form the parent material of soils in many parts of the northern hemisphere but little is known about the histories of these soils. Several methods of estimating soil erosion exist but these have limitations, mainly in that th...

The dune of Oitavos, the underlying paleosol, and Helix sp. gastropod shells found within the paleosol were dated using a combination of radiocarbon and blue optically stimulated luminescence (OSL). The organic component of the paleosol produced a significantly older age (~20,000 cal BP) than the OSL age measurement (~15,000 yr), while 14C age meas...

It is now almost 10 yr since radiocarbon dating of cremated bone was first developed using the small carbonate component contained within the hydroxyapatite-based inorganic fraction. Currently, a significant number of 14C laboratories date cremated bone as part of their routine dating service. As a general investigation of cremated bone dating sinc...

All measurement is subject to error, which creates uncertainty. Every time that an analytical radiocarbon measurement is repeated under identical conditions on an identical sample (even if this were possible), a different result is obtained. However, laboratories typically make only 1 measurement on a sample, but they are still able to provide an e...

The Fifth International Radiocarbon Intercomparison (VIRI) continues the tradition of the TIRI (third) and FIRI (fourth) intercomparisons (Scott 2003) and operates as an independent check on laboratory procedures in addition to any within-laboratory procedures for quality assurance. VIRI is a 4-yr project, with the first suite of samples (grain) se...

The new SUERC AMS Laboratory was described at AMS-9. Since then there have been technological developments, added and improved analysis capability, the formation of additional complementary groups, the purchase of another instrument, and many samples measured. Be, C, Al, Cl, Ca and I-AMS are established with measured species changing weekly. Full-t...

The dune of Oitavos, the underlying paleosol, and Helix sp. gastropod shells found within the paleosol were dated using a combination of radiocarbon and blue optically stimulated luminescence (OSL). The organic component of the paleosol produced a significantly older age (∼20,000 cal BP) than the OSL age measurement (∼15,000 yr), while 14 C age mea...

The issue of comparability of measurements (and thus bias, accuracy, and precision of measurement) from diverse laboratories is one which has been the focus of some attention both within the radiocarbon community and the wider user communities. As a result, the C-14 community has undertaken a widescale, far-reaching, and evolving program of inter-...

Users in the Quaternary and Archaeological Sciences have expressed a general desire for significant improvements in the accuracy and precision of radiocarbon dating results in general but also allied to the measurement of small samples. The accuracy and precision of measurement has also been the focus of some attention within the 14C community. As...

14C measurement uses a number of standards and reference materials with different properties. Historically the absolute calibration of 14C measurement was tied to 1890 wood, through the `primary' standard of NBS-OxI (produced by the National Bureau of Standards, now NIST – National Institute of Standards and technology) subsequently replaced by NBS...

Prior to 1984, the reported marine 14C discharges from Sellafield were estimates: 0.2 TBq per annum from 1952 to 1969 and 1 TBq per annum until 1984 when measurements commenced. The relationship between the net excess 14C activity in annually collected Nori (Porphyra umbilicalis) seaweed samples and the annual discharges (estimated and measured) im...

A new National Electrostatic Corporation (NEC) 5MV accelerator mass spectrometer became operational at the Scottish Universities Environmental Research Centre (SUERC) in July 2002. It has 2 Cs sputter negative ion sources: a 134-sample source (S1) for the routine measurement of all species, and a hybrid source (S2) with 40 spaces for radiocarbon me...

The Sellafield nuclear fuel reprocessing plant on the northwest coast of England is the largest source of anthropogenic radiocarbon to the UK coastal environment. In a mid-1990s study of C-14 distribution around the UK coast, the pattern of dilution with increasing distance from Sellafield appeared to be perturbed by anomalously high C-14 activitie...

Radiocarbon is produced within minerals at the earth's surface (in situ production) by a number of spallation reactions. Its relatively short half-life of 5730 yr provides us with a unique cosmogenic nuclide tool for the measurement of rapid erosion rates ( gt 10(-3) cm yr(-1)) and events occurring over the past 25 kyr. At SUERC, we have designed a...

Prior to 1984, the reported marine 14C discharges from Sellafield were estimates: 0.2 TBq per annum from 1952 to 1969 and 1 TBq per annum until 1984 when measurements commenced. The relationship between the net excess 14C activity in annually collected Nori (Porphyra umbilicalis) seaweed samples and the annual discharges (estimated and measured) im...

A new National Electrostatic Corporation (NEC) 5MV accelerator mass spectrometer became operational at the Scottish Universities Environmental Research Centre (SUERC) in July 2002. It has 2 Cs sputter negative ion sources: a 134-sample source (S1) for the routine measurement of all species, and a hybrid source (S2) with 40 spaces for radiocarbon me...

Radiocarbon laboratories undertake rigorous programmes of internal quality control (QC) and overall quality assurance (QA). In a laboratory "inter-comparison" ¹ samples of the same age are dated at different laboratories using a range of techniques and the results are then compared. The authors summarise the results of the fourth of thes...

The most recent radiocarbon inter-comparison exercise (FIRI), completed in 2001, was also the most extensive so far, with 85 laboratories participating. The study was designed firstly to assess the comparability of the results from different laboratories and then to quantify the extent and possible causes of any inter-laboratory variation. Radiocar...

The issue of comparability of measurements (and thus bias, accuracy, and precision of measurement) from diverse laboratories is one which has been the focus of some attention both within the radiocarbon community and the wider user communities. As a result, the ¹⁴ C community has undertaken a widescale, far-reaching, and evolving program of interco...

Interlaboratory comparisons have been widely used in applied radiocarbon science. These are an important part of ongoing quality assurance (QA) programmes, which are vital to the appropriate interpretation of the evidence provided by the 14C record in Quaternary applications (including climate change and environmental reconstruction). International...

For more than 15 years, the radiocarbon community has participated in a series of laboratory intercomparisons in response to the issue of comparability of measurements as perceived within the wider user communities (Scott et al. 1990; Rozanski et al. 1992; Guiliksen and Scott 1995; Scott et al. 1997). In this report, we provide an update on the cur...

Since the early 1950s, the Sellafield nuclear fuel reprocessing plant in Northwest England has released radio-carbon into the Irish Sea in a mainly inorganic form as part of its authorized liquid effluent discharge. In contrast to the trend in which the activities of most radionuclides in the Sellafield liquid effluent have decreased substantially,...

An on-going inter-comparison programme which is focused on assessing and establishing consensus protocols to be applied in the identification, selection and sub-sampling of materials for subsequent 14C analysis is described. The outcome of the programme will provide a detailed quantification of the uncertainties associated with 14C measurements inc...

Radiocarbon age offsets between foraminifera and bulk carbonate samples were investigated in a sediment core from the western Rockall Plateau in the North East Atlantic. Within the surface mixed layer (SML), foraminifera (forams) ages were significantly younger than those of the bulk sediment at corresponding depths. Below the SML, no significant o...

Prior to this study, almost no up-to-date information was available on the ‘background’ level of 14C present in the water and biota of the UK coastal marine environment. The weighted mean 14C activity derived from the lowest activities of dissolved inorganic carbon (DIC) and biota for sites which are remote from potential sources is 247·6±1·0Bqkg-1...

Prior to this study, almost no up-to-date information was available on the ‘background’ level of ¹⁴C present in the water and biota of the UK coastal marine environment. The weighted mean ¹⁴C activity derived from the lowest activities of dissolved inorganic carbon (DIC) and biota for sites which are remote from potential sour...

Radiocarbon is an important constituent of the low level, liquid, radioactive effluent discharged from the Sellafield nuclear fuel reprocessing plant in northwest England, but despite the fact that it gives the highest collective dose commitment of all the nuclides in the waste, its behavior in the Irish Sea is poorly defined. There is therefore a...

The British Nuclear Fuels plc reprocessing plant at Sellafield in Cumbria, Northwest England, discharges between 1 and 3 TBq of 14C per annum as low-level waste via a pipeline into the Eastern Irish Sea. Our results demonstrate 14C activities in excess of the current ambient level (i.e., ca. 260 Bq kg-1 carbon) in a range of both biotic and abiotic...

The results of this study indicate that scintillation counters employing burst-counting circuitry are capable of producing accurate age measurements. Replicate analyses confirm the validity of the minimum error of 50-60 years quoted on routine age measurements carried out at this laboratory.

The ability of the Packard 2000 CA/LL liquid scintillation counter (LSC) to reduce backround count rates relies on pulse shape/duration analysis in which short duration organic scintillation events are discriminated from longer duration non-quenchable background events. A consequence of this is a loss in the counting efficiency. The results of this...

Prior to 1984, the reported marine 14C discharges from Sellafield were estimates: 0.2 TBq per annum from 1952 to 1969 and 1 TBq per annum until 1984 when measurements commenced. The relationship between the net excess 14C activity in annually collected Nori (Porphyra umbilicalis) seaweed samples and the annual discharges (estimated and measured) im...

C-14 measurement uses a number of standards and reference materials with different properties. Historically the absolute calibration of C-14 measurement was tied to 1890 wood, through the 'primary' standard of NBS-OxI (produced by the National Bureau of Standards, now NIST - National Institute of Standards and technology) subsequently replaced by N...

Unlike 14C that is produced in the upper atmosphere by the 14N(n,p)14C reaction, in situ 14C is produced within minerals at the earth’s surface by a number of spallation reactions including 17O(n,α)14C, 16O(n,2pn)14C and 14N(n,p)14C (Gosse & Phillips, 2001). A range of cosmic-ray produced radionuclides including 10Be, 26Al and 36Cl, which are forme...