Characterization of ageing products of ester-based synthetic lubricants by liquid chromatography with electrospray ionization mass spectrometry and by electrospray ionization (tandem) mass spectrometry.
Ageing products of a commercial jet engine oil based on pentaerythritol tetraesters which were formed upon operation in an aviation turbine were detected by electrospray ionization mass spectrometry (ESI-MS) and characterized by LC-ESI-MS. The fatty acid composition of these ageing products was investigated by ESI-MS-MS analysis. The ammonium adducts of the newly formed pentaerythritol tetraester degradation products were found to be suitable parent ions for further structure elucidation work. ESI-MS, LC-ESI-MS and ESI-MS-MS proved to be versatile tools to study the chemical composition (distribution of homologues) as well as the mechanism of ageing of ester based lubricants on a molecular level. Due to its high sensitivity, ESI-MS can also be used to characterize and identify trace levels of ester-based lubricants.
Kohler
M
M
Swiss Federal Laboratories for Materials Testing and Research (EMPA), Department of Organic Chemistry, Dübendorf, Switzerland. martin.kohler@empa.ch
Heeb
N V
NV
D002853:Chromatography, Liquid / Q000379:methods*; D004952:Esters / Q000737:chemistry*; D008153:Lubrication; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D004952:Esters