Method for the production of acrylonitrile–butadiene–styrene (ABS) and polycarbonate (PC)/ABS standards for direct Sb determination in plastics from e-waste using laser-induced breakdown spectroscopy
This study presents a procedure for direct Sb determination in solid e-waste samples (polymers). Polymer standards (acrylonitrile–butadiene–styrene (ABS) and polycarbonate (PC)/ABS) were mixed with dichloromethane solution for homogenization and then dried, milled and sieved. The obtained powder was mixed with Sb2O3 and pressed in a thermopress. A calibration curve (Sb: 0 to 2.6% w/w) was prepared and analysed using LIBS (laser-induced breakdown spectroscopy) and more than 10 000 spectra were obtained. Carbon (247.856 nm) and Sb (259.805 nm) signals were recorded and normalized by their individual norm values. The best results were obtained when using C as the internal standard and the Sb concentration observed in the samples ranged from 0.15 to 0.68% (w/w). Standard addition tests were performed and the recoveries ranged from 63 to 83%.