Determination of micro metal elements in residual oil by inductively coupled plasma mass spectrometry

A method is established for the determination of Na,Mg,Al,Ca,V,Mn,Fe,Co,Ni,Cu,Zn and Pb in residual oil by inductively coupled plasma mass spectrometry(ICP-MS).An optimum micro-wave systerm is designed for sample digestion.The mass spectrum interference of twelve micro elements in residual oil and possible method for eliminating the interference have also been investigated in detail.The interferences of mass spectrum are minimized or eliminated by selecting different isotope.Internal standard elements such as Sc,Y and Bi are selected for correcting the drift of analytical signals.Under optimum conditions,the detection limits of the twelve elements are found as from 0.001 μg/L to 2.035 μg/L.The linear correlation coefficient r≥0.998 6,demonstrating a good linear relationship.The precision is high(RSD2.3%) and the recoveries are 91%-106%.