Charakteristika kontaminace ostatků kostí pomocí spektrometrie laserem buzeného mikroplazmatu

Bone Remains Contamination Characterisation using Laser-Induced Breakdown Spectroscopy.

abstrakt

en

Laser-Induced Breakdown Spectroscopy (LIBS) has been successfully used to measure element content in various solid materials. This method enables us to gain spatially resolved data, which makes it significant for example in elemental analyses of various archaeological findings (metallic artefacts, glass, pottery etc.) and hard tissue residues. The aim of this work was to measure contents of both major and minor elements in bone tissues in order to characterise external contamination. The elemental composition of bones and teeth also covers trace elements (Sr, Ba, Cu, Zn, Mn) [1]. The bones coming from archaeological sites do not contain the original trace element metal concentration. Due to the diagenesis these fossil bones were enriched during the deposition time in elements typically presented in soil (e.g. Fe, Mn, Cu, Al) [2]. The gradient of soil elements penetration into bones depends on the external conditions, mainly the composition of the surrounding soil, pH, water conditions, microbial activity and of course the character and a degree preservation of the specific bone [3]. The experiment was based on spatially resolved analyses (line scans) of the cross section areas of contaminated bones using LIBS and LA-ICP-MS (Laser Ablation Inductively Coupled Plasma Mass Spectroscopy). Some of the bone samples were excavated from soil, others came from metallic coffins. For this experiment LIBS instrumentation and double-pulse LIBS were used. LA-ICP-MS was applied as a comparative method in order to validate the LIBS outcomes. The results proved that the most remarkable contaminant is copper, which could be regarded as a remarkable indicator of external contamination sources such as copper (or copper alloy) artefacts in a burial ground [4]. Some other elements were present at the sample bones in much higher amounts than the tabulated contents in native bones are, specifically Fe, Mg and Mn. All these elements were preferentially accumulated near the bone surface and their content decreases towards inner cancellous bone. The results showed that the analysed bones were significantly affected by diagenesis and the element distribution gave us evidence on post-mortem alterations.

Práce pojednává o využití analytických technik založených na laserové ablace, konkrétně techniku LIBS, na studium a charaktersitiku kostních ostatků

Laser-Induced Breakdown Spectroscopy (LIBS) has been successfully used to measure element content in various solid materials. This method enables us to gain spatially resolved data, which makes it significant for example in elemental analyses of various archaeological findings (metallic artefacts, glass, pottery etc.) and hard tissue residues. The aim of this work was to measure contents of both major and minor elements in bone tissues in order to characterise external contamination. The elemental composition of bones and teeth also covers trace elements (Sr, Ba, Cu, Zn, Mn) [1]. The bones coming from archaeological sites do not contain the original trace element metal concentration. Due to the diagenesis these fossil bones were enriched during the deposition time in elements typically presented in soil (e.g. Fe, Mn, Cu, Al) [2]. The gradient of soil elements penetration into bones depends on the external conditions, mainly the composition of the surrounding soil, pH, water conditions, microbial activity and of course the character and a degree preservation of the specific bone [3]. The experiment was based on spatially resolved analyses (line scans) of the cross section areas of contaminated bones using LIBS and LA-ICP-MS (Laser Ablation Inductively Coupled Plasma Mass Spectroscopy). Some of the bone samples were excavated from soil, others came from metallic coffins. For this experiment LIBS instrumentation and double-pulse LIBS were used. LA-ICP-MS was applied as a comparative method in order to validate the LIBS outcomes. The results proved that the most remarkable contaminant is copper, which could be regarded as a remarkable indicator of external contamination sources such as copper (or copper alloy) artefacts in a burial ground [4]. Some other elements were present at the sample bones in much higher amounts than the tabulated contents in native bones are, specifically Fe, Mg and Mn. All these elements were preferentially accumulated near the bone surface and their content decreases towards inner cancellous bone. The results showed that the analysed bones were significantly affected by diagenesis and the element distribution gave us evidence on post-mortem alterations.

LIBS,bone remains, contamination

11.09.2011

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