Lubricants reduce surface frictions produced by materials in mutual contact, transfer heat, and carry away contaminants produced in the system. Liquid lubricants contains 90% base oil (often mineral oil from petroleum, but occasionally synthetic oils) and less than 10% additives. The additives in lubricating oils (lube oil) provide different functional properties for the oils such as extreme pressure, corrosion inhibition, anti-foaming, anti-wear, and more. This page provides information on ICP-OES analysis of lubricating oils and contaminants using ASTM D5185.
Lubricant analysis is critical to identify contaminants and wear of metals, and, in industrial use, to determine which additives provide the best oil performance to maintain equipment without damage and disruptions. Regularly scheduled analysis of trace metals, which is produced by engines or equipment, helps identify wear and degradation conditions.
ICP-OES is a powerful tool for analysis of trace metals in lubricating oil because the system:
As part of the oil condition trend analysis, the use of ICP-OES for trace metal analysis in trace metal identification and measurement provides valuable information on the additives and metal wearing, and problems resulting from other sources.
It is important to keep in mind that only oil-soluble metals can be analyzed by the method to achieve accurate and reproducible results.
ASTM standard test method D5185-13 analyzes 22 trace metals in used and unused lubricating oils. The method uses radial view of ICP-OES for fast screening of lubricating oils so timely preventative actions can be taken to avoid serious equipment problems. Analysis time can be further shortened by adding a Sprint valve to speed up sample loading by reducing flushing and rinsing time between samples.