The elemental analysis of oils is an important task for many petroleum laboratories and plays a key role in controlling refining processes. This test method covers the determination of additive elements, wear metals, additive packages and contaminants in used and unused lubricating oils and base oils according to ASTM 5185, ASTM 4951, ASTM 5708 and DIN 51577-5.
Elements to be analyzed vary with the product. In crude oils, sulfur, alkali elements, vanadium, copper, nickel, iron and phosphorus are of importance to characterize the oil and to avoid deactivation of catalysts in the refining process. In lubricating oils, wear metals, such as aluminum, copper, nickel or iron, can indicate wear of any oil-wetted components and it can be determined if the level of wear is critical. Other elements like silicon, magnesium or potassium indicate contamination of the oil. The correct addition of elements, such as molybdenum, calcium, barium, phosphorus and zinc must be monitored and the precision of the analytical results is critical in many cases. In waste oils, the determination of heavy metals, halogens and sulphur is of major importance.
Inductively coupled plasma optical emission spectrometry (ICP-OES) due to its multi element capability, high dynamic linear range, stability and low detection limits is accepted and/or suggested in several standard procedures for oil and fuel analysis. This report shows that the SPECTRO ARCOS MultiView ICP-OES with dual side-on plasma observation is an excellent solution for the fast and simultaneous determination of trace elements, wear metals, additives and chlorine in oil.