Determination of heavy metals in waste lubricating oils by inductively coupled plasma-optical emission spectrometry

In accordance with EU strategy on waste, the utilization of waste oils as a fuel in local power plants has become an interesting choice in hazardous waste treatment planning. The present requirement in Finland is that all oil batches to be burned in power plants must be analyzed for six heavy metals. Thus rapid and cheap methods are needed for these analyses. We have studied and optimized the analytical conditions in the use of sequential inductively coupled plasma-optical emission spectroscopy (ICP-OES) for the quantitative determinations of heavy metals (Cd, Cr, Cu, Ni, Pb, V) in waste lubricating oils. The study showed that using the proposed kerosene dilution method, waste oils can easily be analyzed for heavy metals and the analytical performance of the method is good. In addition, the results suggest that, at least in the case of the Oulu Municipal Waste Management the use of a pair of indictor metals should be sufficient for required determination of heavy metals.