Hi Youssef,

Without detailed of required analysis information (and instrument configuration, sample form, information), difficult to express the suitable protocol for metal analysis.

Anyway, with the Ultrasonic nebulization of samples with kerosene, or Toluene, we can introduce in to the system.

Meanwhile, we need different center tube in the torch for oil analysis.

For analysis protocol, you can refer vendor specific application note with instrument manufacturer.

In sample preparation, we need to manage viscosity of the sample by dilution with organic solvent. The solvent should be of low viscosity, free of analyte impurity, and have low vapor pressure and high boiling point. The solvents which are commonly used are: Xylene, Kerosene, DIBK, MIBK or White spirit.

When the sample require digestion, you can follow the below literature for sample preparation.

"Quantitative Multielement Determination of Metallic Wear Species in Lubricating Oils and Hydraulic Fluids"

Thank you.

S.Afr.J.Chem.,2015,68,76–84 Evaluation of 6 Sample Preparation Methods for Determination of Trace Metals in Lubricating Oils Using ICP-OES

http://www.scielo.org.za/scielo.php?script=sci_abstract&pid=S0379-43502015000100012&lng=en&nrm=iso&tlng=en