reference of calcium in bones is 9-29% and for phosphorus it is 10-12.5%. Can someone give me the reason why in my archaeological bone specimen I got Ca 67.435% and for P 74.094%? What is the reason behind such elevated ca and p concentration?
As an analyst my first question when results are outside usual parameters is: how good is the analysis?
I am perplexed by the numbers you are presenting. 67% + 74% add up to a whole lot more than 100%. And you haven't considered the counter ions. Are you sure your results are in the correct units? Was it measured by XRF and converted to oxides?
Are you sure they are % values? Regardless of the instrument used, you can't have a total of 141%, that doesn't make sense. Are the values you have been given some sort of percentage of a standard value, rather than an absolute concentration in mg/kg?
Perhaps go back to the lab staff and ask what output the instrument provides. Check if they ran a comparison sample to see whether the instrument was calibrated properly to give accurate results.
Was the instrument calibrated for bone material or was it set up for soil or some other material? Did you do any surface preparation of the bone or was it analysed as is? Now I am wondering if the surface of the sample was not oriented correctly and scattered x-rays in all sorts of un-focused directions and you simply have been given poor-quality results.
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