Editing Final Report/Thesis 2018 (section)

==Task 2 Hair Analysis==
===Background Theory===
Analysing elements in the hair could reveal a great deal of useful information on a person’s recent life, this includes their lifestyle imbalances, living environment and dietary problems. Also the mineral levels in hair is about ten times more robust, than compared to blood [26]. These results could reveal where the last place Somerton Man had been to or even the last activity that Somerton Man had done, which could provide some useful evidences in solving this case.  
Knowing how much hair grows is very important for this project. For every month that passes, hair grows by 1cm [27]. This means the newest hair is in the root.

===Aim===
The aim of this task is to identify the different isotopes present in several different people’s hair. More specifically the element of concern is strontium. Adelaide has high levels in strontium in the soil compared to the rest of Australia. With this knowledge, the task is to test various hair samples, which have left Adelaide, within the past month and compare it to that of hair samples that have not left Adelaide for at least a year, to see how the strontium values change. This will then be compared with the strontium levels in the Somerton Man’s hair, which can determine how long he was in Adelaide before his death. The ICP-MS, is the approach to determine the different isotopes within the hair, which will then return a spectral analysis of the hair. The spectral analysis will be completed by laser ablation of the hair, where the hair will be ablated with a laser and the spectral elements are recorded.

===Preparation===
====Hair Elements====
Before the ICP-MS could be used for the analysis on the hair samples, different isotopes had to be chosen for the ICP-MS to find. Research was completed to find the most common chemical elements inside human hair, which included carbon, hydrogen, oxygen, sulphur, phosphorus and zinc. Then further research to indicate what element we want the ICP-MS to find, which included any toxic elements and common elements in food. There were 24 isotopes that were recorded by the ICP-MS and are shown in Table 2.
[[File:ZFigure16.jpg|thumb|500px|center|Table 2. Isotopes chosen for the ICP-MS]]

====Hair Samples====
In this project, a different hair samples was obtained, from five different individuals, for more reliable and accurate results. Two of these samples obtained, were from people that left Adelaide for a period of time and the other three samples were from people that stayed in Adelaide. All the samples will be anonymous for privacy reasons and will be identified as A, B, C, D and E. A summary of each hair sample is shown in Table 3, this includes which sample is identified as, sex, the date the hair was obtained and a brief description of the sample.
[[File:ZFigure17.jpg|thumb|500px|center|Table 3. Summary of the samples]]
The length of time out of Adelaide is very important, as we can determine the length of hair that was in Adelaide and the length of the hair that was outside of Adelaide. Sample A left Adelaide for 7 days, assuming there is 30 days in one month and hair grows 1cm per month, therefore 2.33mm of hair is from Japan. Similarly with sample E, they left Adelaide for 13 days, therefore 4.33mm of hair is from Bali. Also have to take consideration of the 2 days from when they came back to Adelaide to when the hair was obtained, this is 0.67mm. An example of the length of the hairs is shown in Figure 15.
[[File:ZFigure18.jpg|thumb|500px|center|Figure 15. Example of the hair length]]
The red displays the 2 days before obtaining the hair, when both samples came back to Adelaide. The orange shows the length of sample A and the green shows the length of sample E, when both samples were away from Adelaide.

====Quartz Slide====
The hair samples will be placed on a slide, in this case the slide will be made of pure quartz. The reason a pure quartz slide is used, rather than an ordinary glass slide is that, glass slides have a lot of impurities that would contaminate the result, where as a pure quartz slide does not. The elements in a glass slide and quartz slide is shown in Table 4.
[[File:ZFigure19.jpg|thumb|500px|center|Table 4. Comparison of elements in glass and quartz slide]]
The hair samples were stuck down with double sided sticky tape on the quartz slide, this will have some contamination and will have to be dealt with appropriately.

===Mass Spectrometer Experiment===
====Capturing the data====
The quartz slide was placed into two stabilisers, which was then installed into the machine. This machine did the laser ablation on the hair samples. Figure 16 displays the quartz slide with the hair samples, installed into the laser ablation system. While Figure 17 displays the enlarged version of the quartz slide on the monitor.
[[File:ZFigure20.jpg|thumb|500px|center|Figure 16. Hair samples installed into the laser ablation system]]
[[File:ZFigure21.jpg|thumb|500px|center|Figure 17. Laser ablation system with monitor]]
Next to the laser ablation system, there are two monitors which will be used for the laser ablation task. The left monitor records the data of the laser ablation and the right monitor controls the laser ablation system, this can be seen in Figure 18. The next step involved choosing how many spots of the hair we want ablated and the distance between these spots. A spot is where the laser will ablate the hair and the isotopes will be recorded for that spot. It was chosen to ablate the hair about half way (1cm), which gave 11 spots at about 800 micro meters apart, two of these spots were located in the root. The mass spectrometer will then document the chosen isotopes. The complete set up of the experiment is shown in Figure 19, with the laser ablation system on the left and the mass spectrometer on the right.
[[File:ZFigure22.jpg|thumb|500px|center|Figure 18. Recording the data (left) and controlling the laser ablation machine (right)]]
[[File:ZFigure23.jpg|thumb|500px|center|Figure 19. Agilent 7900x mass spectrometer with attached New Wave NWR213 laser ablation system]]

====Processing the Data====
The data from the ICP-MS was then put into a software called Iolite, this is how we managed the data and removed any anomalies [29]. The overall waveform of the isotopes in the hair sample for several spots can be seen in Figure 20. An enhanced and zoomed in version of one of the spots is shown in Figure 21.
[[File:ZFigure23.jpg|thumb|500px|center|Figure 20. Waveform of the isotopes in several spots]]
[[File:ZFigure24.jpg|thumb|500px|center|Figure 21. Enhanced and zoomed into a spot]]
A brief explanation of the waveform composition will be done. Each waveform is an individual isotope, where the top waveform is the average of all the other waveforms. The first 20 seconds of the waveform, shows a relative flat line, this is the laser ablation system calibrating itself. This information is not useful. The waveform peaks up (represented with a square box), this is when the laser just hits the surface of the hair. Then the waveform is a flat line, this is when the laser is ablating the inside of the hair. This is the important information. In some cases the waveform peaks up at the end, this is the laser ablating through the hair and onto the sticky tape and quartz slide.
To compare the results more precisely, two sets of data were captured, the surface of the hair and inside the hair. Only getting these results, meant there was so contamination from the sticky tape or the calibration set up. Lastly the results were outputted into one comprehensive Excel file, with all the necessary data, a portion of the data can be seen in Figure 22. 
[[File:ZFigure25.jpg|thumb|500px|center|Figure 22. Portion of the data]]

===Data Analysis===
Analysing the data, there were several isotopes that were found in the hair, these isotopes are shown in Table 5.
[[File:ZFigure26.jpg|thumb|500px|center|Table 5. Isotopes found in the hair]]

====Strontium====
The comparison of the strontium in the different samples can be seen in Figure 23.
[[File:ZFigure27.jpg|thumb|500px|center|Figure 23. Strontium in different samples]]
The x-axis represents the distance of the hair ablated and the y-axis is the amount of strontium in the hair at that distance. Samples A and E, are the samples that left Adelaide and came back. 
For sample E about the first 4000um of hair is when they were in Bali, except for the very first point where they were in Adelaide. Observing the figure, sample E has two high peaks of strontium levels, one at about 1500um and the other at about 3200um, this indicates that there is high strontium levels in Bali. The rest of the value of strontium are low, when sample E came back to Adelaide.
For sample A about the first 2000um is when they were in Japan, except for the very first point where they were in Adelaide. Observing the figure, there is a peak at about 1500um, indicating higher strontium values, than that of when sample A was in Adelaide.
Overall, these results are concluding that the strontium levels in Adelaide are smaller than that of Bali and Japan.

===Conclusion===
The strontium level is lower in Adelaide than that of Bali and Japan. Relating this to the Somerton Man, as pervious groups did the ICP-MS on his hair and got high strontium reading. This indicates that Somerton Man must have visited another country with high strontium level, before his visited Adelaide.