” Lubricating oils are given specific functional properties by mixing additives with base oil. In order to assure consistent and desirable performance, it is very important to control the concentrations of the additives during the lubricant manufacturing process.
X-ray fluorescence (XRF) spectrometry has become increasingly popular for quantitative elemental analysis of base oils as well as additives and lubricant products thanks to its high precision and simple sample preparation. With liquids, sample preparation for XRF typically means pouring the sample into a plastic cup equipped with a transparent film. Unlike traditional techniques, such as Inductively-Coupled Plasma Optical Emission Spectroscopy (ICP-OES), XRF does not require chemical decomposition, digestion or serial dilution. ASTM D6443-04 specifies the use of the wavelength-dispersive (WD) XRF technique, because it offers sufficiently high precision, resolution and light-element sensitivity to meet the industry’s needs.
Traditionally, WDXRF spectrometers have been large, floor-standing models with substantial installation requirements and high cost of component replacement. In its search for greater cost-efficiency, the lubricant industry is turning to tools that not only do the job, but are also easier and less expensive to acquire, install and maintain.
This application note demonstrates the capability of low-cost, compact benchtop WDXRF spectrometer for quantitative elemental analysis of Ca, Cl, Cu, Mg, P, S and Zn in base oils, lubricating oils and additives”