Loading effect of matrix compounds in aerosol LIBS measurements

In this work the effect of concomitant mass present in the probe volume on the Cu I LIBS signal in aerosol isstudied for a correct interpretation in the quantitative analysis. Mg, Cr and Na are considered as matrix elementsand the effect on the emission line is investigated increasing the loading of the elements with respect to copperconcentration. Moreover, the role of the specific matrix compounds employed is also analyzed comparing Nachloride and Na acetate. The peak and base of Cu I LIBS signals as well as their corresponding peak/base ratiosare detected increasing the concentration of the matrix compounds under analysis. To explore this matrix effecton the plasma, the temporal analysis of the peak and base of the Cu I emission line is performed with and withoutchromium in the highest concentration under analysis. Finally, temperature measurements are carried out in thedifferent matrix conditions at relatively short delay time considering nitrogen neutral lines. The results obtainedhighlight the effect of the concomitant mass present in the probe volume, essentially related to the physicalproperties of the compounds considered. These properties can affect plasma conditions changing the temperatureand the plasma temporal evolution, and ultimately affecting the LIBS signal.