Learning Stable Isotopes One Failed Sample at a Time: The Messy Reality of Uncovering the Past

My doctoral research explores an 18 th -19 th century Muslim cemetery from Constanța, Romania, with the aim of understanding how people lived and adapted within an Ottoman frontier community during a period of imperial decline. By combining osteological evidence [1], historical sources and stable isotope analysis [2], I can investigate aspects of people's lives that are difficult to reconstruct from bones alone, particularly their diets and mobility. There was just one problem: when I began writing the proposal, I barely understood how any of this actually worked.

More than half of my samples had failed to yield collagen [3], likely due to poor preservation, the rest were lost somewhere in Europe and all I had to start with were questions. Standing in the laboratory, I wondered whether there was any point continuing something I had so clearly underestimated. Looking back, I realise that learning stable isotopes was never really about mastering laboratory techniques. It was about discovering how research actually works: slowly, unpredictably and often through what seems like a failure.

Writing the Proposal

The project fascinated me because it offered a new way of understanding how people adapted to life on the Ottoman frontier. The challenge was not only explaining why isotope analysis could answer these questions, but also working out how I would collect and prepare the samples and produce reliable results. The process felt strangely backwards: I had to convince specialists that I understood exactly what I was doing when the reality was quite the opposite.

So, I had to start somewhere and began by researching the basics. It wasn't impossible; what proved difficult was learning how the method worked in practice and what was required to produce reliable data. I attended isotope classes, read everything I could find and spent countless meetings with my supervisor asking what felt like very basic questions.

I began drafting the proposal, but each paper that answered one question seemed to raise three more. Despite months of research and attempts to turn my ideas into a convincing plan, the rejection email eventually arrived. It confirmed what I had begun to suspect: I had underestimated the challenge.

With even less hope and confidence than I had in the beginning, I started rewriting the application while also making alternative plans in case it failed again. The second attempt was no easier; I second guessed every sentence. In the end, I submitted it again because I felt I had nothing to lose.

Learning Journey

Securing the funding felt like crossing the finish line until I realised I was only just starting. The fear of not securing funding gave way to the fear of putting theory into practice.

Although the reality was messier than I care to admit, there was no longer room to simplyunderstand what I had to do; I had to carry it out correctly for dozens of samples at a time.

The laboratory work began with problems I had not anticipated. Some samples were lost between Romania and the UK, laboratory supplies were delayed and carefully planned schedules fell apart. Despite repeated attempts to retrieve the samples, I eventually had to return to Romania and begin again.

Until then, I had assumed that following the protocol carefully would naturally lead to successful results. Ironically, every sample in the first batch yielded collagen. With little time to celebrate this success, I began processing the second batch, hoping it would run just as smoothly now that I had already been through the process once.

I could not have been more wrong. More than half of the samples in the second batch failed to provide any collagen. Even after repeating the extractions, several samples still refused to cooperate. Instead of fluffy collagen, they produced a sticky substance that clearly wasn't right. The failed extractions forced me to realise that laboratory work is rarely that predictable. A protocol provides a framework, but it cannot eliminate the uncertainty that comes with archaeological material. I began to understand that failure was not necessarily a sign that I had done something wrong, but an inevitable part of working with the past. Research rarely goes to plan and learning to adapt when things go wrong is part of the process. 

Working alongside the isotope specialist, we decided to make one final attempt to recover them. To my surprise, most were saved. I realised that knowing when to seek another perspective was just as important as knowing how to follow a protocol. What I could not solve on my own became possible through collaboration, reminding me that research also involves learning from others. Adapting to unexpected challenges does not always mean finding a solution on your own; sometimes, it means recognising when to ask for help.

The laboratory work may be complete, but the most meaningful stage still lies ahead: turning these results into new insights about the community I study. This process has reminded me that there is still far more I do not know than I do and this experience has made that clearer than ever. But unlike when I first began writing the proposal without really knowing what I was doing, I now understand that not knowing is not the end. More often than not, it is where research truly begins.

Three years ago, I thought stable isotopes were simply another laboratory technique that would help me delve into interdisciplinary research. Today, I see them differently. They have taught me as much about research itself as they have about the people I hope to understand.

Andreea Toma is a PhD candidate in the School of History, Philosophy and Digital Humanities at University of Sheffield. Her research is funded by WRoCAH. She would be very happy to hear from anyone interested in her work and can be contacted at  atoma1@sheffield.ac.uk.

References

[1] Osteological evidence refers to information obtained from the study of human skeletal remains, including biological sex, age at death or pathological manifestations.

[2] Stable isotope analysis: a scientific method that measures naturally occurring variations in chemical elements preserved in archaeological remains. These patterns can provide information about aspects of past people's lives, including diet and mobility.

[3] Collagen is a protein that makes up much of the organic component of bone. When sufficiently preserved, it can be extracted from archaeological bones and analysed for stable isotopes.

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