Date of Submission

5-8-2025

Document Type

Thesis

Advisor

Ashley Morgan

Keywords

thermal decay, chemical composition, bones, ATR FT-IR spectroscopy, DNA extraction

LCSH

biodegradation, biochemistry, bones, DNA--analysis, bones, femur, polymerase chain reaction

Abstract

This research was designed to determine the effect of thermal decay on the chemical composition of pig femur bones. Two methods were utilized to observe the effect of thermal exposure on burnt samples: ATR FT-IR spectroscopy and DNA extraction with PCR quantitation. The former utilizes infrared spectroscopy with an attenuated total reflectance sampling method to measure a sample’s absorption of IR light. This allows for a better understanding of a material’s composition by providing information about its chemical bonds and functional groups. DNA extraction from samples can also provide information through PCR quantitation, in which the amount of genetic material present within a sample is amplified. It was hypothesized that as the temperature at which the samples were exposed increased, the bone composition would exhibit higher levels of decay due to dehydration, denaturation, and degradation of organic compounds. It was therefore expected that as temperature increased, a decrease would be observed in CO/P ratio calculated from ATR FT-IR peak intensities as well as the quantity of DNA able to be recovered through PCR. Four pig femur bones were utilized in this experiment and cut into three cross sections prior to burning. One cross section each from bones 1-3 were burned at three temperatures, ranging from 100˚ to 280˚C. Cross sections from Bone 4 were left untouched as unburned control samples. Powdered bone samples were collected from each cross section, which were then used for ATR FT-IR spectroscopy and DNA extraction. Both methods of information collection were completed successfully and indicated that an increase of temperature resulted in a slight increase in CO/P ratio and quantity of DNA extraction from 100˚C to 200˚C, before a significant decrease in each from 200˚C to 280˚C. It was also found through analysis of control samples that natural variation has a large effect on the data and should be minimized in future studies. Natural variation acts as a random variable, and when controlled, will allow for a greater understanding of the effects of temperature on the samples.

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Available for download on Friday, May 08, 2026

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