In forensic research analysis is performed on teeth or bone.
The ratio of strontium isotopes in dental enamel of the permanent dentition is formed during the first decade of life and is stable for the rest of the person's life.
The strontium in bone undergoes continuous replacement and so the ratio of strontium isotopes reflects where the patient has lived more recently.
Analysis:
(1) concentration of strontium-87 (dependent on decay of rubidium-87)
(2) concentration of strontium-86 (not dependent on radioactive decay)
ratio of strontium isotopes =
= (strontium-87) / (strontium-86)
The ratio is expressed to 5 or more decimal places depending on the accuracy of the chemical analysis.
Interpretation:
• A native person would have ratios in permanent dentition and bone the same as the locale.
• The region of the person's origin can be suggested based on the isotopic ratio.
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Dental Compared to Locale
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Bone Compared to Locale
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Dental Compared to Bone
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Origin
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same
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same
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same
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native
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different
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different
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same
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recent immigrant
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different
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same
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different
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remote immigrant
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different
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different
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different
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recent immigrant who has lived in at 2 places
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same
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different
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different
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native who has lived elsewhere but returned
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