ICP-MS Determination of Metal Elements in Used Lubricating Oil

The sample of lubricating oil was treated in a quartz beaker by ashing at 350 ℃, 450 ℃ and 550 ℃, respectively, and then digested with HNO3 and HClO4. The contents of Al, Ba, Cu, Cr, Cd, Fe, Mg, Mn, Mo, Ni, Pb, Sn, Sb, Ti, V and Zn in the sample solution were determined by ICP-MS. The interferences and matrix effect were corrected by choosing suitable isotopes. Values of detection limit (3s) found were in the range of 5-100 ng·g-1. The proposed method was applied to the analysis of sample of used lubricating oil, giving values of recovery and RSD′s (n=12) in the ranges of 95.6%-104% and 0.34%-2.3% respectively.