Abstract: An analytical method using ICP-MS for the determination of trace metals in lubricating oils emulsified by TritonX-100 is established. After the experimental conditions and instrumental parameters were optimized and the internal standard solutions are added, the emulsified samples were then introduced directly into the plasma. The addition of internal standard is to eliminate the matrix effect caused by samples emulsified and standard solutions. The inorganic-metallic standard solution is used for calibration instead of expensive organic-metallic standards. The established method shows the advantages of easy-handle, good precision and accuracy. The recoveries are 90-110%. The RSD of all elements is less than 7.0%. The results of this method are in good agreement with those obtained by organic-metallic standard solution.

Key words: lubricant oil, metallic elements, emulsion sampling directly, ICP-MS