Flame tests and emission spectroscopy (LW2)

In labwork 2 we used an atomic absorption spectrometer in order to quantify copper amount in soils. The analyte was atomised using a flame at high temperatures. This flame can also be used to “excite” atoms. In this case, the electrons of the atoms jump to a higher energetic level and when returning to their original level they release energy in form of light. Since this energy is element dependent, it can be useful to obtain information about the composition of a sample. In the laboratory, we observed the colour of the flame of different salts containing: lithium, boron, sodium, potassium, calcium, copper, strontium and cesium.

The emission of energy is not only useful to obtain qualitative information, but also quantitative. The energy released by a specific analyte can be measured at a certain wavelength and employed for quantitative purposes. That is the basis of atomic emission spectroscopy (AES). Finally, just let you know that this phenomenon is used to make fireworks. Here you have a nice infographic by Compound of Interest.