Time-Resolved Laser-Induced Breakdown Spectrometry for the Rapid Determination of Beryllium in Beryllium-Copper Alloys

Abstract

Time-resolved laser-induced breakdown spectrometry has been combined with the long spark technique and applied to the rapid determination of beryllium in beryllium-copper alloys. A calibration curve was developed which related the beryllium concentration in a solid copper matrix to the Be(I) 234.9-nm to Cu(II) 235.7-nm intensity ratio. The beryllium concentrations ranged from 0.001 to 0.22%. For the lowest concentration the relative standard deviation of replicate samples was 7%, implying a detection limit of 0.0002% (2 ppm) at a signal-to-noise ratio of 3. The excitation temperature was determined from Boltzmann plots on Cu(I) and Cu(II), assuming local thermodynamic equilibrium. The values from the two spectra agreed well, and averaged to 13,850 K at 1 μS into the plasma lifetime.