“…The sponge samples, as well as the standards, have a high content in light elements (H, C, N and O) which in spite of being non-detectable by the EDXRF technique have to be taken in consideration to correct California, 1990), corrects the light element absorption on the basis of the mean atomic number of the sample, which is determined from the ratio of the incoherently and coherently scattered intensity radiation by the sample (O'Reilly and King, 1986). For this purpose six pellets of pure compounds (C 6 H 10 O 5 , H 3 BO 3 , NH 4 NO 3 , (NH 4 ) 2 SO 4 , NaF and Na 2 SO 4 ) were used to establish the correlations between the intensities of the Compton and Rayleigh scattered X-rays of the Ag secondary target by the irradiated sample with the average atomic number (Z).…”