Discrimination of organic solid materials by LIBS using methods of correlation and normalized coordinates

► In this work parameters LIBS has been optimized for discriminating organic solid materials. ► The present study demonstrates that LIBS is capable of characterizing organic solid materials with similar chemical composition. ► LIBS has the potential to discriminate one from the other by means of the methods of linear and rank correlation and method of normalized coordinates. The methods of linear and rank correlation and normalized coordinates (MNC) have been applied to the identification of organic solid materials with a very similar chemical composition by laser-induced breakdown spectroscopy (LIBS). The present study evaluated these three statistical methods using an Echelle spectrometer coupled with an intensified charge-coupled device (ICCD). Moreover, three instrumental parameters (laser pulse energy, delay time and integration time) were evaluated in terms of their influence on the signal-to-noise ratio of carbon and hydrogen emission lines. The probability of a right identification can be estimated by means the described methods in this paper. Methods of correlation provide better identification and discrimination than normalized coordinates at a 95% confidence level.