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.

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 .

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

Studying the diet of an animal that roams the Earth today is relatively straightforward. Their eating habits can be easily tracked and their food sources monitored using their faecal matter (‘scat’). But how do you study the diet of animals that have been dead for thousands of years? The NERC/51ÁÔÆæ-funded project ‘Hungry like a wolf’, carried out by BGS together with Royal Holloway University London, aims to do exactly that: study the diets of wolves that lived in Britain during the last 250 000 years.

Investigating ancient animals’ diets

The project adopts the adage ‘we are what we eat’. The type of diets an animal consumes are imprinted on the wear and tear on their teeth and the stable isotope signature in their body tissues. For animals that are no longer alive, studying these signatures in fossil bones and teeth provides a window into the animal diet and consequently into how their diets have changed over time with fluctuating climatic and ecological conditions. The project aims to understand how wolves have adapted to changing environments by comparing the diet of past (10 000 to 250 000 years) and present wolves, along with other predators and prey from different locations across Europe.ÌýÌý

Top ice age predators

Although they were the first animals to be domesticated by humans, wolves were well-established members of the Pleistocene (ice age) carnivore community in Europe. As one of the top predators, wolves keep the populations of their prey in check and, as a knock-on effect, affect the biodiversity of other predators in the area as well as other animal and plant species further down the food chain by limiting over-predation and over-browsing on vegetation. Wolves are therefore considered the most influential large predator in the northern Eurasia region.  

Project aims

Unfortunately, many surviving populations of these charismatic animals are today endangered because of human persecution and environmental change. Serious concerns exist as to the viability of European wolf populations under different scenarios of environmental and climate change. It is therefore essential to understand how wolves have adapted to changing circumstances in the past, so that current and future conservation policy can be appropriately tailored.

The project is being carried out by Dr Angela Lamb and Dr Diksha Bista at BGS, together with Prof Danielle Schreve, Dr Fabienne Pigière and Dr Amanda Burtt (Royal Holloway University London). It will involve museum collections from across the UK.

The collections housed here at BGS were some of the first to be analysed. These collections comprise Quaternary (up to 2.58 million years ago) subfossil bone material that has been held in the museum since the late 1800s. Specimens were collected from Ilford by Richard Payne Cotton and donated in 1877, whilst those from Crayford are from the collection of Frederick Spurrell, donated in 1894.

Although the material was collected over 150 years ago, advancing research technologies allow us to uncover new information that can enhance our understanding of past environments and ecosystems. Even though the subsampling involves removing a small amount of material from the selected bones, the insights gained from the analysis can add significantly to the understanding of the fossils held in the collection since the Victorian era.

Louise Neep, BGS Museum Curator.

Laboratory analysis

In the laboratory, collagen will be extracted from the bones and analysed for nitrogen (N), carbon (C) and sulfur (S) isotopes. Recent technical developments within the Stable Isotope Facility now allow the measurement of these isotopes on a significantly smaller amount of collagen (10 times smaller). This advance means much less sample needs to be removed from the fossils, thus preserving the integrity of precious museum specimens.Ìý

Acknowledgements

We’d like to thank Paul Shepherd (collections manager) and Simon Harris (conservator) for their support with the project.

About the authors

My name is Christopher Bengt and I am first-year PhD student enrolled at Lancaster University and I am being hosted at the BGS by the Stable Isotope Facility. My PhD is funded through the and the 51ÁÔÆæ University Funding Initiative. My research aims to understand fundamental questions about how tropical forest composition, structure and flowering dynamics are affected by the concentrations of essential nutrients, importantly phosphorus, in the soil. 

My previous research 

Prior to taking this post, I completed my master degree (MRes) in biological science at Birkbeck, University of London, where I studied the extraction of DNA from archaeological animal bones. This work involved using a number of analytical methods to assess the level of damage to the bones, indicating the extent of preservation of ancient DNA. Whilst studying, I also worked on immune response to vaccines and infectious diseases as a laboratory technician at the World Health Organisation Pneumococcal Serology Reference Laboratory at University College, London. All these skills stand me in good stead for my PhD, which will have significant laboratory and fieldwork requirements.  

Tropical rainforests 

Tropical rainforests are the oldest living and most complex ecosystems on Earth, with evidence from fossils and pollen dating back 70 million years. Being in the tropics, the rainforests have a stable climate consisting of warm temperatures, high precipitation levels and high levels of solar irradiation, providing essential conditions for highly productive forests. The stable climate, abundant resources and millions of years of evolution mean biodiversity in tropical rainforests has flourished, resulting in countless species with specialised adaptations.  

The effect of volcanoes on tropical ecosystems 

Unexpectedly for such diverse and productive ecosystems, rainforest soils are often of poor quality, with low concentrations of nutrients including carbon, nitrogen, potassium, and phosphorus. However, in areas such as the Philippines (my study area), volcanic eruptions can deposit nutrient-rich ash directly into the tropical rainforest environment. Volcanic ash is composed of fine rock particles that can be expelled and then deposited over vast areas, many kilometres from the original site of eruption. These particles contain essential nutrients such as potassium and phosphorus, and it is hypothesised that these may be critical for soil enrichment.  

Whilst volcanic eruptions can pose an immediate threat to local ecosystems, the aftermath may help foster these fertile environments. The relationship between volcanoes and nutrient-rich soils underscores the dual nature of these natural phenomena that are both destructive and transformative.  

Past records of climate 

To better understand the relationship between volcanoes and tropical ecosystems, we must explore past records of volcanic activity and forest productivity. These are often best found within lake sediment archives.  

Lakes serve as repositories of environmental history through the sediments that accumulate at their bottoms. The sediments are composed of organic and inorganic materials and encapsulate a wealth of information, telling us about crucial nutrients (including phosphorus) and serving as archives of ecological changes. My project will analyse both the nutrient makeup of the lake sediments and the ancient DNA preserved within them. In combination, these records will allow us to investigate the links between nutrient dynamics, ecosystem productivity and plant and tree diversity.  

For my project, I will undertake a fieldtrip to Lake Bulusan at Mount Bulusan, one of the most active volcanoes in the Philippines, which is surrounded by rainforest. Cores of the sediment from the lake will be brought back to the UK to interrogate the geochemical signatures trapped within them. The sediment cores will also be sent to the University of Copenhagen, Denmark, to extract and analyse modern and ancient DNA.  

These records should tell us more about how climate, volcanic activity and biological history are linked throughout the last 2000 years. This multiproxy approach will uncover critical information regarding the modern phosphorus cycle and soil limitations, as well as the true impact volcanic events have had on the phosphorus cycle in the palaeorecord and, in turn, the development and flowering of the surrounding tropical forest. The findings could potentially offer a ‘step change’ in our understanding of tropical forest development in volcanically active regions.  

About the author

Christopher Bengt is a first-year PhD student enrolled at Lancaster University. His PhD is funded through the and the 51ÁÔÆæ University Funding Initiative.

In July, I started my role as a stable isotope research assistant at the National Environmental Isotope Facility (NEIF) at BGS headquarters in Keyworth, Nottinghamshire. 

Before I took on this role, I was studying for my PhD in ocean and earth science at the University of Southampton. My project involved the use of stable isotopes as part of a multi-proxy study to reconstruct climatic and environmental changes in tropical South Pacific islands during the late Holocene. The aim was to try and identify periods of drought and whether they were related to the timing of human migration across the tropical Pacific.  

During the course of my PhD studies, I took part in a placement scheme that enabled me to gain experience working in the stable isotope facilities at BGS, learning preparation protocols and getting some hands-on experience with mass spectrometry. This enabled me to have a smooth transition into my new role as a stable isotope research assistant.

My new role so far has primarily involved analysing organic samples for the stable isotopes of carbon and nitrogen with Dr Jack Lacey. We work with a range of samples including lake sediments, ocean sediments and plants. The sample preparation involves using acid to remove any inorganic carbon from the sediment; the acid is then washed-out using water and the samples are dried. Following this, they are ground and weighed into small tin capsules ready for analysis. The data these analyses produce will provide scientists with information such as changing environmental conditions through time, including changes to vegetation, productivity and human effects on environmental systems.  

These samples are analysed using our Isoprime PrecisION with Elementar vario ISOTOPE cube, which calculates the percentage carbon (C) and nitrogen (N) content, as well as the stable isotope values for δ¹⁵N and δ¹³C. This system works by combusting the samples at 950°C so they transform into gas. The gas is then passed through a series of traps that remove any unwanted contaminants or water and reduce the gas down to the elements we want to measure. The gas is then passed through to the mass spectrometer, where it is measured against a monitoring gas. This has let me experience independently running the organics mass spectrometer, giving me the chance to learn more about the system, and offers regular problem-solving opportunities. 

I have also had time to learn the process for running the small carbonates mass spectrometer with our geochemistry technician, Kotryna Savickaite. This has involved working with very different materials such as corals, shells and other marine organisms. It has been good to get involved with other aspects of the varied work we do at NEIF and expand on my skills and knowledge in this area. 

Everyone in the stable isotope team has been friendly and welcoming and I am keen to continue learning more about the work that goes on at BGS and get involved with some cool science.  

About the author