Sliding-spark spectrometry of sediment samples

Direct analysis of non-conducting solids and dielectric surface layers for elements at trace levels has been shown to be feasible by the new so-called sliding-spark spectroscopy, in which a discharge plasma is bound by, and propagates on, the surface of a dielectric sample matrix. By using a river sediment as a model matrix, bound in PVC to improve elemental atomization and excitation efficiency, as a result of the formation of volatile chlorides, the potential of the technique for environmental applications has been investigated by studying the characteristic UV-visible radiation emitted in the wavelength range 210-510 nm for the elements Fe, Cr, Ni, Cu, Pb, Cd, Zn, Co, V, Ti, and Mn. The radiation was detected by means of a CCD spectrometer and analysed for spectral line identification, selection, and the linearity of the spectral response, to determine whether this was suitable for establishing a calibration strategy for quantitative analysis using the sliding-spark source.