In chemistry student Dorontina Domi first couple of months of her placement at BGS, she has rotated between different laboratories including organics, collagen extraction and modern environmental gas analysis. This has provided her with a broad experience of the different instruments and sample preparation techniques that are required within BGS Stable Isotope Facility (SIF). In this blog, Dorontina tells us about some of her experiences so far. 

Carbon and nitrogen isotopes in organic materials

A wide array of instruments in the SIF can be used to analyse the carbon (C) and nitrogen (N) isotope composition of organic materials found in sediments, soils and plant materials. The bulk of the analysis is carried out using an Elementar isoprime precisION isotope ratio mass spectrometer (IRMS) with a vario ISOTOPE cube elemental analyser (EA). The samples are combusted in the EA and are then passed onto the IRMS on a continuous flow of helium carrier gas, selected for its inertness and separation efficiency for measurement.

While learning sample preparation, I gained experience in using microbalances to weigh samples down to 200 micrograms (or 0.0002 grams), which is a miniscule amount that is challenging to see with the naked eye. I compacted the weighed sample material into either crucibles or capsules, depending on the instrument and their auto sampling methods.

When analysing these sample materials for C isotopes, it is important to understand whether the results are representing organic or inorganic C fractions contained in the material. Organic carbon consists of compounds sourced from living organisms and their remains, and inorganic carbon, such as from carbonates, is formed from biological and geological processes. The two forms of C have very distinct isotope compositions (inorganic C typically has more carbon-13 compared organic C) and even a small amount of inorganic C contamination in samples can offset target organic C isotope values.

Samples must therefore be treated to remove inorganic C prior to isotope analysis. I acidified samples using hydrochloric acid (HCl) and rinsed them with purified water, using a centrifuge to ensure thorough washing, until the pH tested neutral. This process dissolves the inorganic C fraction and isolates the organic C fraction.

SIF houses 13 mass spectrometers, so I have also gained experience in how staff conduct maintenance, such as on the Elementar IRMS. I assisted in replacing the consumables to ensure that the analyses are performed with a high precision and accuracy.

Carbon, nitrogen and sulfur isotopes in prehistoric bone samples

Comparing carbon, nitrogen and sulfur isotope ratios from carnivores and their prey allows us to distinguish the palaeo-diet of animals and the of different species. This allows us to interpret their relationships during different ages and draw inferences from the data on changes associated with climate differences. For example, the higher the nitrogen isotope composition (δ¹⁵N) the more ‘carnivore-like’ feeding habits took place, therefore the main prey for each species can be identified.

Statistical tools called Bayesian mixing models will be used as a framework to integrate the large proportion of data from throughout modern and Pleistocene times and to infer the relevant data. Through this, the project will assess how changes in climate and environment influenced the feeding behaviour of the wolves and their resilience during reductions in prey availability. This information is crucial to understand the influence climate change will have on the endangered species in the future and help conservation strategies.

As part of the sampling programme, I was given an opportunity to spend a day at the laboratories in London, where I observed the meticulous drilling process used to cut small pieces of material from a variety of different fossil species for later analysis. The samples were cut from areas that will minimise damage of the structural integrity of the bone for conservation purposes.

As well as fossil samples, the project is also analysing contemporary wolves from Croatia and their prey as a comparison. These samples are less than 100 years old and required an initial solvent treatment in the geomicrobiology lab before collagen extraction could begin.

I have also helped to prepare the samples for isotope analysis, where a multi-step process takes place to extract the collagen, before it is purified and analysed via the EA-IRMS.

Carbon isotopes in methane samples

Another aspect of my training coversÌýanalysing methane (CH₄) gas samples for their carbon isotope composition using a Sercon HS2022 with CyroGas.

This instrument works by purifying the sample gas via carbon dioxide (CO₂) traps and a cryogenic gas trap to remove any other sources of carbon present that are not from CH₄, thus reducing potential sources of contamination. The sample gas then flows through a combustion tube, where the CH₄ is converted to CO₂ and cryogenic trapping takes place, ensuring that the CO₂ is concentrated in the final trap and can be released to the mass spectrometer rapidly. This allows for a narrow, sharp peak that can be analysed and replicated with a high precision. I also hope to help with the analysis of hydrogen (H) isotopes via the pyrolysis of CH₄ to H₂.

Working at BGS as a student

If you are an undergraduate student looking for an opportunity within stable isotopes, I highly recommend BGS. Not only is it the largest UK producer of stable isotope data, but it is also a supportive workplace to be a part of. There are a variety of clubs to involve yourself in such as the BGS Wilding Group. Staff and volunteers maintain the natural areas at BGS to promote wildlife biodiversity, as a commitment to sustainability.

I would like to extend a massive thank you to everyone at the Stable Isotope Facility for welcoming me with such support and excitement. It has been an incredible start to the placement and I am looking forward to the rest of the year!

About the author 

Dorontina Domi is an undergraduate chemistry student at the University of Surrey, completing her industrial placement at SIF, which is located at BGS headquarters in Keyworth, Nottinghamshire. 

I recently had the opportunity to attend and present at the 13th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC XIII) in Kailua-Kona, Hawai’i, USA. This conference is an international forum for discussing advances in radioanalytical chemistry and its applications.

As a PhD student, attending MARC XIII was an invaluable experience. The conference gave me the opportunity to share the latest findings of my project, as well as to engage with researchers from all over the world and gain insights into nuclear forensics and analytical chemistry.

During the conference, I delivered a presentation entitled ‘Exploring the analysis and diagnostic value of oxygen isotopes for nuclear forensics’. My talk focused on the method development of microfluorination, which enables precise oxygen isotope analysis using minimal sample sizes. I discussed the optimisation of the fluorination reaction, thereby improving oxygen yields and the relevance of this technique to forensic investigations of nuclear materials.

The method I have been working on has the potential to enhance the nuclear forensic toolkit by providing reliable oxygen isotope signatures from oxide materials, including heavy metal oxides. I also shared preliminary results from test samples and outlined plans for applying the method to other laboratories.

As well as presenting, I attended various sessions covering topics, including: Ìý

• environmental radioactivity measurements
• activation analysis
• radiation detectors and instrumentation
• nuclear proliferation prevention and safeguards
• mass spectrometry methods for detecting radioactive materials

It was inspiring to experience the interdisciplinary nature of the field and to see how researchers are pushing the boundaries within radiochemistry.

One of the standout moments of the conference was a student networking event that brought together students and researchers from various US national nuclear laboratories. It was a fantastic opportunity to have informal, face-to-face conversations with professionals from places like , , and . As a student based outside the USA, I found it incredibly valuable to learn more about the kinds of research being done at these institutions and to hear about career pathways, postdoctoral opportunities and collaborative projects.

Of course, being in Hawai’i added to the experience! While most of the time was dedicated to sessions and discussions, I managed to take some time to enjoy the spectacular surroundings, which made the conference even more memorable.

Attending MARC XIII was a valuable experience that allowed me to engage with the global research community. The feedback and connections I gained will undoubtedly shape the next stages of my PhD research. I’m excited to follow up with the researchers I met and to explore potential collaborations. I look forward to future conferences and events in the field of radioanalytical chemistry.

About the author

Paulina is a third-year PhD student at BGS and the University of Nottingham. Her PhD is funded by AWE.

Soil reference materials (RMs) are critical to ensuring the accuracy and consistency of analytical results across laboratories and research institutions. BGS has produced ten new soil RMs, which have been developed by its inorganic geochemistry team to offer a cost-effective alternative to traditional certified reference materials (CRMs), while maintaining confidence in analytical data. The RMs have been released at a lower price point to help improve access to high-quality materials for researchers and laboratories with limited budgets, enabling them to enhance measurement controls and increase confidence in analytical results across a variety of sectors worldwide. 

Developed from a broad selection of parent materials and incorporating a diverse range of textures and organic carbon contents, reference soils BGS110 to BGS119 have each been characterised by a select group of international laboratories using a variety of analytical techniques. The RMs are also accompanied by data sheets that include for 64 major, minor and trace elements, including rarely measured bromine and iodine. More information about the ten new RMs can also be found in the new report, .

Reference materials are the backbone of geochemical analysis, providing confidence in the measurements that a laboratory produces. Our RMs offer reliable benchmarks for analysing samples with similar matrices. Due to their diverse concentrations of economically and environmentally significant elements, these RMs will enable laboratories, PhDÌýresearchers and industry professionals to calibrate instruments, validate analytical methods and ensure data comparability across studies.

Dr Michael Watts, head of BGS Inorganic Geochemistry.

51ÁÔÆæ now has 18 soil RMs (including one for use in and seven for the analysis of ) and five mineral RMs available for purchase through its website.

The inorganic geochemistry team also remains actively engaged in global initiatives to harmonise soil analytical data across laboratories. These efforts support enhanced health outcomes and food security worldwide. BGS produces custom proficiency testing (PT) materials for international PT schemes coordinated by the Food and Agriculture Organization of the United Nations’ (GLOSOLAN). As part of its collaboration with the FAO-UN and other organisations, BGS has delivered laboratory training around the world, including guidance on producing RMs and PT samples. A free, publicly available is accessible via the GLOSOLAN website.

In addition, BGS prepares geological PT samples and CRMs for a number of commercial distributors, supporting both UK and international PT schemes.

To place an order or for more information on our bespoke RM and PT preparation services, please contact the inorganic geochemistry team (inorganicgeochemistry@bgs.ac.uk). (Gamma irradiated soil RMs are available on request for shipping internationally.)

The University of Nottingham has appointed BGS senior isotope research geochemist, Angela Lamb, as an honorary professor. As part of her role, Angela will contribute to undergraduate and postgraduate teaching alongside facilitating collaborative research programmes between BGS and the University of Nottingham.

Angela research focuses on the application of light stable isotopes to science-based archaeology, palaeoecology and environmental tracing, specialising in sulfur isotopes. She has developed a long-standing collaborative relationship with the University of Nottingham Department of Classics and Archaeology through the jointly operated Centre for Environmental Geochemistry. The centre focuses on the collaborative use of geochemistry in research, training and teaching, investigating:

• environmental and climate change
• biogeochemical cycling, including pollution typing and provenance
• science-based archaeology
• the use of geochemical tools for research into the subsurface

I’m thrilled to have been appointed as an honorary professor at the University of Nottingham and look forward to continuing to build on the legacy of shared research we have developed through the Centre for Environmental Geochemistry. This has already resulted in significant advances in the fields of bioarchaeology, palaeoecology and environmental archaeology.

Prof Angela Lamb, senior isotope research geochemist, BGS.

We’re delighted to welcome Angela Lamb as an honorary professor in the department. We have had a long and productive relationship with Prof Lamb and very much look forward to this continuing in the future. We are particularly excited to develop our work in dietary stable isotope analyses, which help us to understand what people and other animals ate and how societies functioned in the past.

Prof Hannah O’Regan, professor of archaeology and palaeoecology, University of Nottingham.

The Stable Isotope Facility (SIF) at BGS has just welcomed a new arrival to its mass spectrometer contingent: Elementar isoprime preciSION with iso DUAL and iso MULTI PREP instrument. It is designed to analyse carbon and oxygen isotopes from carbonates as well as oxygen isotopes in waters for scientific research.

The instrument

We have nicknamed our new instrument ‘Gemini’ to reflect both its nature as a and its dual purpose to analyse both small carbonates and water isotopes. Since being installed in April 2025, it has already analysed over a thousand samples and is able to run a range of in-house and international standards with better than 0.1 per mil reproducibility down to a sample size of 20 Î¼g (potentially even less than 5 Âµg! It is very difficult to see materials at this weight). Gemini has already successfully analysed a range of sample materials including tooth enamel, foraminifera, brachiopods and clam shells for various research questions.

Testing the Gemini

As part of the initial setup, we ran a series of tests to ensure the Gemini was running well. This included a size test that looks at what the values are for one standard if we weigh it out across a range of sizes. For this test, we used an in-house standard Keyworth Carrara marble (KCM), which is a calcite. Carrara marble has been used for building since ancient Roman times because of its beauty and it present in many notable structures, including Marble Arch in London, Peace Monument in Washington DC, the Pantheon in Rome and grave headstones across the world — we are currently using an offcut from a stone mason. Our batch is a valuable standard for oxygen and carbon carbonate analysis not just in SIF but also in many laboratories across the UK.

Figure 3 shows the data produced during the size test. The reproducibility was better than 0.1 per mil for both δ¹³C and δ¹⁸O across a range of sample sizes, which is excellent news and conforms with the precision required for internationally reporting of stable isotope data.

Research focuses

We use carbon and oxygen isotopes in carbonates (CaCO₃) to understand more about our environment both today and in the past. Recent published work on carbonates that the stable isotope team have been involved with include:

• using brachiopod isotope composition  to reconstruct environmental variation in the (past) oceans ()
• identifying changes in rainfall over thousands of years using cave stalagmites in Iraq ()
• describing changes in oxygen levels in ancient oceans ()

If you are interested in reading about other research done by the Stable Isotope Facility, please visit our for our publications.

If you are a potential user of Gemini, please contact the Stable Isotope Facility. UK-based researchers can apply for access through the (NEIF), which is a NERC Service and Facility and free at the point of access for successful UK applications. The next deadline for NEIF applications is 8 October 2025. Before submitting your application, it is important that you first seek the advice of staff at the facility. Further information can be found on .

The mysteries of Stonehenge have baffled scientists for centuries. In the 2010s, archaeologists and geologists identified two quarries in Wales as the sources of Stonehenge legendary standing bluestones. Now, new evidence published by scientists in August 2025 consolidates this connection.

A century ago, in 1924, archaeologists discovered a cow jawbone that had been carefully placed beside Stonehenge south entrance and dated it to the monument very beginning in 2995 to 2900 BCE. The discovery has intrigued historians ever since. Why had it been placed there? Why was this animal considered special? Researchers from BGS, Cardiff University and University College London have used isotope analysis to bring this artifact to life, helping to reveal further tantalising glimpses into the origins of the historic landmark.

The scientists sliced the cow third molar tooth, which records chemical signals from the animal second year of life, into nine horizontal sections. They were then able to measure carbon, oxygen, strontium and lead isotopes, which each offer clues about the cow diet, environment and movement.

The oxygen isotopes revealed that the tooth captured roughly six months of growth, from winter to summer, whilst the carbon isotopes showed the animal diet changed with the seasons: woodland fodder in winter and open pasture in summer. Additionally, the strontium isotopes indicated the seasonal food sources came from different geological areas, suggesting that the cow either moved seasonally or that winter fodder was imported.

The lead isotopes revealed composition spikes during the late winter to spring, pointing to a lead source that was older than the lead in the rest of the tooth. The composition suggests the cow originated from an area with Palaeozoic rocks, such as the bluestones found in Wales, before moving to Stonehenge.

This is the first time that scientists have seen evidence linking cattle remains from Stonehenge to Wales, adding further weight to theories that cows were used in the transportation of the enormous rocks across the country.

This study has revealed unprecedented details of six months in a cow life, providing the first evidence of cattle movement from Wales as well as documenting dietary changes and life events that happened around 5000 years ago. A slice of one cow tooth has told us an extraordinary tale and, as new scientific tools emerge, we hope there is still more to learn from her long journey.

Prof Jane Evans, BGS Honorary Research Associate.

In addition to this discovery, researchers also concluded that the unusual lead signal could not be explained by local contamination or movement alone. Instead, there was another explanation: that lead stored in the cow bones had been remobilised during the stresses of pregnancy. If true, this would mean the cow was female and pregnant or nursing during the tooth formation. To test the hypothesis, the team applied a peptide-based sex determination technique at the University of Manchester, which showed there was a high probability that the animal was female.

This research has provided key new insights into the biography of this enigmatic cow whose remains were deposited in such an important location at a Stonehenge entrance. It provides unparalleled new detail on the distant origins of the animal and the arduous journey it was brought on. So often grand narratives dominate research on major archaeological sites, but this detailed biographical approach on a single animal provides a brand-new facet to the story of Stonehenge.

Richard Madgwick, professor of archaeological science at Cardiff University.

Stonehenge has many secrets left to be uncovered. However, this latest research helps fill in just a few more of those gaps as we learn more about this legendary landmark.

This is yet more fascinating evidence for Stonehenge’s link with south-west Wales, where its bluestones come from. It raises the tantalising possibility that cattle helped to haul the stones.

Michael Parker Pearson, professor of British later prehistory at University College London.

The research paper, , is now available to read.

Carbon and oxygen isotopes in carbonate are a useful tool that can tell us about our environment. For example, oxygen isotopes in tooth enamel are useful in archaeology when researchers want to find out where individuals they are working on are from, or to track animal movement and husbandry. We can also use this technique to analyse modern-day shells of molluscs such as whelks or scallops, to see how they are adapting to rising sea-water temperatures as a result of climate change. Ìý

Stable isotope analysis at BGS

The Stable Isotope Facility at BGS can analyse a range of carbonate types, including tooth enamel, speleothems, calcite minerals and a wide range of shells, for carbon and oxygen isotopes. We currently have several instruments that can analyse carbonate materials including very small samples down to 5 micrograms — which would fit on the head of a pin!  

During analysis, laboratory staff need to check whether the sample data produced is accurate. We do this by analysing standard materials that have a predetermined value in every sample batch. Both the samples and standards are analysed using the same method, so if the standard data is accurate and precise, the sample data should be correct. Standards are also used to correct data if there is a measurement offset from the known value. We use multiple standards to cover the range of our sample isotopic values.   

Why do we need in-house standards? ​  

We are developing new in-house (internal) standards to use in our laboratory for three reasons. Firstly, we analyse thousands of samples each year, which means we need a lot of standard material. International standards provided by external bodies can be expensive and can run out, so creating our own standards internally helps decrease costs and makes sure there always enough standard material available.  

Secondly, because we analyse some unusual carbonates, it is best to have a standard that matches the sample material we are measuring. Finally, there are very few oxygen isotope standards currently available for carbonates, especially carbonate in tooth enamel. This is because carbonates in powder form exchange oxygen with the atmosphere, causing carbonate isotope values to change over time, meaning materials used for standards do not last long.   

What are we testing?

We are currently working on developing three new internal carbonate standards that we can use as a reference material for our work.

The first is Bahamian oolite aragonite, which we call BOA for short, which comes from a beach composed of oolitic sand in the Bahamas. BOA is composed of round and tiny, egg-shaped ‘ooids’, which form in warm shallow seas and are then deposited on the beach.

The second is made up of fragments of whelk shells, (sometimes known as sea snails). The shells we have are waste from the fishing industry, where the whelk is removed and sold as food and the shells are repurposed for decorative use and in gardening.

The third and final material is from a high-temperature skarn (HiTS) rock that has come from western Romania. This rock formed when magma heated limestone bedrock from below, producing a skarn punctuated with calcite veins, which we extracted. ​This material is probably the most valuable to us as it has a very low oxygen isotope composition, making it useful as a reference material for archaeological tooth enamel samples, as they tend to have low values. 

Creating the internal standard

To use these new materials as an internal standard, we need to ensure that they meet certain requirements:  

• they have homogenous​ carbon and oxygen isotope values   

• there is an isotopic and chemical match to routine samples​  

• they are affordable, available, accessible and abundant  

• they are chemically and isotopically stable over time  

To make sure we meet these requirements, we have been working with other teams within BGS to help characterise our materials. So far, we have analysed them using our scanning electron microscope and X-ray diffraction, which tell us about what elements  make up these materials to check for impurities.  

We are currently analysing our three new standards at the Stable Isotope Facility over an extended period of time, to ensure that they produce consistent isotope values. So far, we have values with an error of less than 0.2 per mil, which is great news for the possibility of the Stable Isotope Facility laboratories and others in the organisation using these materials as an internal standard in future carbonate research. We hope to make these new standard materials available to other stable isotope facilities soon!

Contact

Please get in touch with either of the authors if you are interested in participating in an interlaboratory comparison, to enable us to certify the values of these new standard materials. 

About the authors

My week began with a welcome tour of the research facilities at BGS and, more specifically, the geochemistry laboratories. The team provided an introduction to the field of mass spectrometry and the use of isotopes in archaeological research. The sample preparation, which happens under very precise, controlled conditions to exclude contamination, involves a huge amount work prior to analysis. It wasn’t long before I was gaining hands-on experience working with carbon isotopes from organic and inorganic materials, preparing samples and then analysing them on mass spectrometers. For me, one of the highlights was learning how to handle samples down to 40 micrograms in weight — which I can confirm is difficult to see with the naked eye!  

Geoarchaeology 

Dr Angela Lamb is well known for being one of the leading geochemists on the research into and analysis of King Richard III remains. She took the time to talk to me about the relevance and application of geochemistry in archaeological contexts. In relation to King Richard III, her detailed analysis has revealed various fascinating details about his life, for example that he lived in different locations through his childhood and into his adult years. Bones in our bodies reflect our diet and location (due to the underlying geology that creates different soil chemistries in different areas) and this type of analysis has been used in countless archaeological investigations — as featured in the TV programme ! Ìý

The BGS collections 

I was also taken on a tour of the BGS collections by Louise Neep. It was so exciting to see them in person, especially the vast fossil collections. Louise explained how conservation methods have evolved since the 18th century. I was able to see fossils that are up to 500 million years old and inspected ancient plants, trilobites and an ichthyosaur. It was thrilling to hold such ancient relics in my hands. Louise gave me a real appreciation for all the curation efforts that are taken by BGS staff members like Louise to preserve the relics for future scientific research.  

The week ended with an excellent conversation with Dan Condon, who works on dating meteorites. He explained how uranium–lead dating is used and the physics and chemistry involved, which was particularly relevant to my aspirations to be an astrophysicist.  

Overall, this was a very informative and exciting week that introduced me to various facets of laboratory life, which is very different to what we see at school. It has enhanced my understanding of which skills are essential for laboratory work, for example the high-precision, detail-oriented work on the samples, and the importance of handling scientific data. The week made me appreciate science methods and gain confidence that research in astrophysics is the ideal career for me.  

Thanks 

Thanks to all the staff at BGS who were very helpful, especially Charlotte Hipkiss, Jack Lacey, Kotryna Savickaite, Diksha Bista, Dan Condon, David King, Doris Wagner and Carol Arrowsmith. 

About the author 

Riveen Pehesara Kumanayaka is an aspiring astrophysicist who is currently studying for his A levels in physics, maths, computer science and English literature.