Detection of environmental contaminants by time resolved laser induced breakdown spectroscopy technique

Laser induced breakdown spectroscopy (LIBS) has become a reliable tool for very fast multi-elemental pollutants' analysis. Its principle of operation lies in the avalanche ionization effect produced by an intense laser beam focused on the sample to be investigated. Under the effect of the intense EM field of the laser, the material is separated into its atomic constituents, with a very high degree of ionization and electron temperatures reaching several tens of eV. With the recombination of atoms and electrons, an extremely intense emission of right (laser spark) takes place. The latter is collected and analysed for discerning the characteristic emission lines of the different elements in the sample. It may be appropriate to quote the possibility of getting quantitative information on the whole sample composition in a single run, through the simultaneous detection of the emission line patterns of different elements present in the material under analysis. This peculiar feature of the LIBS system allows for very fast sample analysis and thus, when necessary, for continuous monitoring of its composition. The applications of the LIES technique to industrial exhaust monitoring take great advantage of these characteristics, along with the possibility of LIBS operation in hostile environments. It is possible to arrange a setup in which the most delicate parts of the apparatus are kept protected in a safe environment far apart from the dangerous and/or potentially damaging site to be monitored. Remote operation is also useful in polluted soil and water analysis.