Raman spectroscopy of metallic ferromagnetic foreign bodies extracted from the human body: identification of materials, biocorrosion products, and assessment of clinical hazard
Varvara V Dudenkova 1, Maxim G Ryabkov 1, Evgeny O. Bazhenov 2; 1 Privolzhsky Research Medical University, Nizhny Novgorod, Russia; 2 Nizhny Novgorod State Technical University, Nizhny Novgorod, Russia
Abstract
Metallic foreign bodies retained in the human body undergo biocorrosion, potentially leading to inflammation, fibrosis, and systemic toxicity. Identification of the material and its transformation products is crucial for predicting clinical complications.
This study employed a comprehensive approach combining X-ray fluorescence analysis (XRF) and Raman spectroscopy of both the surface and cross-sections (fresh cuts) of ferromagnetic fragments extracted from patients to assess their potential danger. XRF was performed using a portable X-MET 8000 analyzer (Oxford Instruments, UK). Raman spectra were recorded using an NTegra Spectra setup (NT-MDT, Russia) equipped with an Eclipse Ti2 inverted microscope (Nikon, Japan) and a Confotec NR500 spectrometer (SOL Instruments, Belarus). Excitation was provided by a 532 nm laser (6.8 mW under objective, 600 lines/mm grating, 180 s exposure) in the 100–3900 cm⁻¹ range. Phase identification was based on literature data.
Analysis of 20 samples revealed 40G, 60S2, and 09G2S steels; AK4 and AK9 aluminum alloys; ChVG 35 cast iron; and Fe–Cr–Mn and Fe–Ti–Si–P alloyed steels. Biocorrosion products—goethite, magnetite, biogenic phosphates, and organic deposits—were detected on all steel surfaces. Carbide phases (cementite, alloyed cementite) and graphite inclusions were identified in cross-sections. A classification by risk level was proposed: high-risk (active corrosion, phosphates, carbides), medium-risk (moderate changes), and low-risk (passivation, biocompatible composition).
We conclude that combined surface and cross-section Raman analysis enables not only metal identification but also detection of biocorrosion markers that determine clinical risks.
The study was supported by the Russian Science Foundation, project No. 26-15-00510.
Speaker
Dudenkova Varvara
Privolzhsky Research Medical University
Russia
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