Laser-Induced Breakdown Spectroscopy (LIBS)
LIBS is a fast, non contact and micro destructive elemental chemical analisys technique. The analysis consists in focusing a lasar pulse on the surface of a sample. The very high power density leads to the formation of a plasma composed of free electrons, atoms and excited ions. The atoms and ions emit photons whose wavelength is characteristic of the chemical element by de-exciting themselves. The light emitted by the plasma is then collected and analyzed by a spectrometer. The detected emission lines are used to identify the elements present in the sample (qualitativeanalysis). Their intensity can also be measured anc ompared to that measured for a range of samples of known concentration, un order to measure the elemental composition of the sample (quantitative analysis). Finally, the overall spectrum can be used to determine the nature of the sample, usually using multivariate analytical methods (material recognition).
The portable system is the SciAps Z 300 GeoChem Pro system which used a Nd:YAG laser operated at 1064 nm with an energy under 6mJ/pulse and a frequency of 50Hz. The Spectral range is between 190 and 950 nm (continuously), with one or more lines from all elements in periodic table.