This works because ethyl acetate is an organic compound and therefore, it is a solvent that would easily dissolve other organic compounds. The washing with ethyl acetate would bring the organic compounds into the liquid phase, while the inorganics and insolvents would stay in the solid phase. By putting the contents through a filter, the liquid organic layer was separated from the solid insoluble layer. The resulting liquid organic layer is set aside to be tested.
The resulting solid insoluble component is put through a similar process, only this time, instead of ethyl acetate, distilled water is used. The distilled water is a polar solvent, so it will be able to extract and dissolve the inorganic metal compounds from the leftover soil. The result is a liquid layer composed of water and dissolved inorganics, and the solid insoluble "sand."" The resulting mixture is put through a filter to separate the dissolved inorganics from the solid sand. The resulting liquid is set aside for both quantitative and qualitative analysis.
Water was not used first in our separation technique because one of our organic compounds, m-nitroaniline, were slightly soluble in water (we guessed that we had m-nitroaniline and naphthalene due to our soil's distinctive color and odor). Had we used water first, the liquid layer from the separation would be composed of both inorganics and some organics, requiring us to perform extra separation techniques again on the water solution. None of the inorganics were soluble in ethyl acetate so we were sure that there would be no contamination of our organic layer.
Isolating Organics.
To first confirm that our organic layer did indeed contain m-nitroaniline and naphthalene, we ran a TLC test on our organic solution alongside the pure compounds. The solvent for the mobile phase was a 2:5 ratio of hexane and ethyl acetate. Results showed that the two compounds in our solution was highly likely to be the two compounds we guessed.
