Use laser induced breakdown spectroscopy in detection of heavy metals contents in Sudanese cement

Abstract

Cement is an important industrial product in construction, streets, roads, bridges, etc. It is of great importance, so it is necessary to know its heavy metal components. In this work, Laser Induced Breakdown Spectroscopy (LIBS) was used to detect, and identify, the heavy metals in Sudanese cement samples that collected from different local markets in Khartoum state. Four cement samples were used as study samples (Atbara, Barbar, Mas and Sakhr Al Sudan) cement. Nd: YAG laser in Q-switched mode was used as the laser source. The laser parameters were 8 ns pulse duration time, 10 Hz pulse repetition rate, 266 nm laser wavelength and 30 mj pulse energy. Ocean Optics LIBS 2000+ system was used as spectrometer. The detector has a gated CCD camera having 14,336 pixels. At a 90°angle to the laser pulse the emission spectra was observed. The recorded spectra samples were analyzed using NIST data. Neutral atoms Like (Ca, Fe, Si, Na, Ti, Cr, V, Sr, Zr, Kr, K and Cs) that were detected from the analysis of samples spectra. that were found in all samples. In addition to the ions: (Ca+1, Fe+, Si+1, Na+1, Ti+1, Cr+1, and K+1). The heavy metals like: metals (Cr, Fe, Ti, Mn, V, Xe, Y and Zn) were appeared in the four samples. To identify the relationship between the laser pulsed energy and the intensity of the LIBS signal, the Mas cement sample was irradiated by different pulse laser energies (10, 15, 20, 25, 30 and 32 mJ). Respectively and 200 ns delay time. We observed when the laser pulse energy increase the line intensity of the LIBS was increase.