Detection of trace elements in nondegradable organic spent clay waste using optimized dual-pulsed laser induced...

The detection of trace elements present in nondegradable organic spent clay waste has been carried out using an optimized dual-pulsed laser induced breakdown spectrometer. The two laser pulses at 1064 and 266 nm were collinearly collimated and focused on the sample surface in order to enhance the signal intensity. The atomic transition lines at 568.8 nm (Na-I), 504.2 nm (Pb-II), 405.8 nm (Pb -I), 443.56 nm (Ca-I), 469.41 nm (S-I), 520.8 nm (Cr-I), 643 nm (Cd-I), and 928.1 nm (Cl-I) were used as marker wavelengths, and the concentrations of 688, 300, 204, 460, and 2440 ppm of Pb, S, Cd, Cr, and Cl, respectively, were detected in the 5% spent clay in the binder. The limits of detection of Pb, S, Cd, Cr, and Cl were estimated to be 6.7, 17.2, 6.5, 5.1, and 14.8 ppm, respectively, from the calibration curve for each element. In order to confirm the reliability of our system, the concentrations of the reported elements detected using our system were compared to the ones obtained with inductively coupled plasma emission spectroscopy and found to be in good agreement.