title: Hypernated supercritical fluid chromatography: potential application for car lubricant analysis.
abstract: Car lubricant additives are added to mineral or synthetic base stocks to improve viscosity and resistance to oxidation of the lubricant and to limit wear of engines. In previous papers related to this purpose, it was demonstrated that SFC allows the elution of common low molecular weight additives. Since their total resolution could not be achieved owing to the limited peak capacity of packed columns, the hyphenation of selective and informative detectors, atomic emission and mass spectrometry, were also carried out for identification. This paper describes the final implementation of a packed column SFC/FID-UV-AED-FTIR-MS system to contribute to the characterisation of both the base stock, mineral or semi-synthetic, and the low molecular weight additives. SFC/FID-UV-FTIR ensures the easy confirmation of the presence of esters in the base stock. Reference additives are used to demonstrate the performances of the multi hyphenated system prior to its implementation for their identification in packages and in formulated lubricants. Identification and partial structure elucidation of additives and families of additives in package and formulated car lubricants are presented: using combined information obtained from AED traces and FTIR chemigrams, chemical families of additives can be deduced. Then, the mass spectra can be interpreted in the elution zone of interest in order to go further in the determination of the additive molecular structure. The hypernated SFC system was also employed to follow the ageing of car lubricants.
authors.affiliation: Laboratoire Chimies Analytiques Bioanalytiques et Miniaturisation (UMR PECSA CNRS-UPMC, ESPCI #7195), ESPCIParisTech, 10, rue Vauquelin, 75231 Paris Cedex 05, France.
authors.forename: Gwenaelle
authors.initials: G
authors.lastname: Lavison-Bompard
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bertoncini
authors.forename: Didier
authors.initials: D
authors.lastname: Thiébaut
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Beziau
authors.forename: Bernadette
authors.initials: B
authors.lastname: Carrazé
authors.forename: Pascale
authors.initials: P
authors.lastname: Valette
authors.forename: Xavier
authors.initials: X
authors.lastname: Duteurtre
mesh_terms: D001336:Automobiles; D025924:Chromatography, Supercritical Fluid / Q000295:instrumentation / Q000379:methods*; D054327:Lubricants / Q000032:analysis* / Q000737:chemistry; D013058:Mass Spectrometry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D054327:Lubricants