Calibration free laser induced plasma spectroscopy: a new frontier for material analysis, environmental protection and Cultural Heritage conservation.

A new calibration free procedure (CF-LIPS) for quantitative elemental analysis of material, based on laser induced plasma spectroscopy technique, has been developed and patented by the pulsed laser spectroscopy group at IFAM/CNR (Pisa). This procedure allows for fast and reliable quantitative analysis of materials in solid, liquid or gaseous phase. Precision of order of a few parts percent can be obtained, for all the elements in the samples, with typical sensitivities of one part per million or better. Major constituents, trace elements and impurities are all measured in the same run. The two major advantages of the CF-LIPS technique, compared with conventional chemical analysis methods, are the independence on samples pretreatment and calibration curves. The problems related to the so-called 'matrix effect', which produces a lack of linearity in emission spectra, are completely overcame by the application of this standardless analytical procedure, which is based on the measure of the relevant physical quantity characterizing the plasma. These features make CF- LIPS an eligible method for on-line elemental analysis or in field quantitative measurements. In fact, CF-LIPS is the only existing technique which gives precise quantitative results, comparable with laboratory chemical analysis, in real time and in situ. The comparatively low cost of the system, along with its intrinsic speed and ease of use, will probably help, in next few years, a further diffusion of the calibration-free LIPS technique for material analysis, environmental protection and Cultural Heritage conservation and study.