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Publication
Towards the understanding of the impact of pH on age estimation
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| 2.55 MB | Adobe PDF |
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Advisor(s)
Abstract(s)
The first steps in human remains identification are the determination of age, sex, ancestry and stature. Of these, determination of age is crucial as it facilitates the development of a biological profile be it in archaeological remains or recent forensic matters. Teeth with their hard exterior can protect useful information and store this information for years after death, though environmental conditions may affect the information within.
In addition to developing and optimizing a method for quantifying and determining the proportional ratio of amino acids present in teeth by Gas-Chromatography-Mass spectrometry.
An introduction of new techniques for the diastereoisomeric separation of D- and Lenantiomers of aspartic acid were tested for use with GC-MS with and achiral column and GCFID with a chiral column.
On top of this a novel technique was used to determine the racemic mixture percentage of D- and L- aspartic acid. Circular Dichroism was used to measure the racemic content in samples which were submitted to various temperatures in pH solutions of 3, 5 and 9 for a time interval of 72hours. Results obtained demonstrate occurrence of racemization in temperatures of 80 ℃ and above as well as the differential effect produced by acidic and alkaline pH solutions.
It would be interesting to discover if with a more sensitive technique, such as GC-MS, and an experiment with a longer time interval a significant change between pH could be demonstrated as well as comparing the difference in racemization rate between free and bound aspartic acid.
Description
Dissertação de Erasmus Mundus para obtenção do grau de mestre em Técnicas Laboratoriais Forenses
Keywords
Biological profile pH Human remains identification Forensic laboratory