Laser-based method for the determination of precious metal concentrations in metals

摘要

The invention pertains to a process and a device for determining the composition and concentration of elements in material samples using laser-based plasma emission spectroscopy. The process comprises the following steps: a) transformation of a portion of the material sample (20) to a plasma-like state (46) by means of a pulsed high-power laser (12) focussed on the material sample (20); b) spectral analysis of the radiation emitted by the plasma (46) using a spectrometer (26); c) measurement of the total emission spectrum (44) of the plasma (46) changing per laser pulse in one or more spectral ranges typical of the element, using a detector (40); and d) calculation of the composition and concentration of the elements based on the entire spectrum (44) of measured emissions, i.e. the sum of a number of measured individual spectra (42). The claimed device (10) comprises a high-power laser (12), a spectrometer (26) and at least one measuring head (14) with integrated radiation optics (22). The high-power laser (12) and the spectrometer (26) are geometrically and stereoscopically decoupled from the measuring head and are connected to each other via at least one waveguide.