Soil research: atomic absorption spectrophotometry

 

When an electron from the inner shell of an atom is excited by the energy of a photon, it moves to a higher energy level. When it returns to the low energy level, the energy which it previously gained by the excitation is emitted as a photon which has a wavelength that is characteristic for the element (there could be several characteristic wavelengths per element). Analysis of the X-ray emission spectrum produces qualitative results about the elemental composition of the specimen. Comparison of the specimen's spectrum with the spectra of samples of known composition produces quantitative results (after some mathematical corrections for absorption, fluorescence and atomic number).

 

With the help of the geomorphology department of the University of Heidelberg, we applied this technique to establish the differences in chemical composition in eighteen soil samples taken around the city of Mannheim. The goal was to measure the degree of Phytoremediation occurring in Sorel plants that were cultivated in these soil samples over the period of a year, and correlate these results with the variations in colour of the natural dye these plants produced

 

Work in progress.