Rapid analysis of lubricants by atmospheric solid analysis probe–ion mobility mass spectrometry

Abstract

Formulated lubricants are complex mixtures composed of base oil(s) and additives with various functions (detergents, corrosion inhibiter, antioxidant, viscosity modifiers, etc.). Because of the aliphatic nature of base oil and the chemical diversity of additives, the characterization of lubricant is currently a long and complex process. The comprehensive analysis of lubricant samples involves several techniques such as nuclear magnetic resonance, mass spectrometry, chromatography and infrared spectroscopy. The coupling of atmospheric solid analysis probe (ASAP) with ion mobility-mass spectrometry (IM-MS) has been shown to be an efficient tool for the characterization of complex mixture containing vaporizable polar to non-polar compounds. This approach affords the coupling of a direct ionization technique that does not require sample preparation, with a bi-dimensional separation method with high peak capacity. In this work, we show that ASAP-IM-MS is a suitable method for rapid and direct characterization of lubricant samples. Indeed, base oil and additives yielded, by ASAP, ions series which could be separated by IM-MS. Molecular additives such as Zn-dithiocarbamate, phosphite, thiophosphate and Alkyl diphenylamine were ionized as molecular ions [M](+•) or protonated molecules [M + H](+), depending of their polarity. In some cases, fragment ions were observed, confirming the additive identification. In addition, high molecular weight polymeric additives such as poly(alkyl methacrylate) (PAM) were pyrolized in the ASAP source leading to characteristic fragment ions. ASAP-IM-MS is shown to be a powerful tool for studying complex mixtures, allowing the first comprehensive analysis of lubricants in just a few minutes.

High‐performance thin‐layer chromatography with atmospheric solids analysis probe mass spectrometry for analysis of gasoline polymeric additives

“…Since 2005, ASAP has grown in popularity since it permits the direct analysis of a wide range of samples and in particular polymers. [29][30][31][32][33] For instance, synthetic polymers have been efficiently analysed using ASAP and their polydispersity evaluated. 34 More recently, a rapid characterization of various polyalphaolefin samples was reported using ASAP coupled with ion mobility spectrometry -mass spectrometry (IMS-MS).…”

Multidimensional Mass Spectrometry of Synthetic Polymers and Advanced Materials

“…The ASAP method has been successfully applied to characterize highly fluorinated polymers, blends of biodegradable polyesters with polyethylene, formulated lubricants, insoluble poly(ether ether ketone)s, and grafting on cyclic olefin copolymers . Preliminary data on polyurethane and styrene–butadiene elastomers further reveal that ASAP‐IM‐MS can provide important insight into the composition and additives of industrial thermoplastics, based on which similar products of distinct origin or from different batches can be conclusively identified …”

Molecular Fingerprints and Speciation of Crude Oils and Heavy Fractions Revealed by Molecular and Elemental Mass Spectrometry: Keystone between Petroleomics, Metallopetroleomics, and Petrointeractomics

“…33,34 IMS-MS has proven to be an efficient method for rapidly characterizing petroleum samples without the requirement of sample pretreatment 35 or preparation. 36 By comparing a feed and a process product, Maire et al 37 highlighted the presence of PASHs by using IMS-MS. The same approach was utilized to characterize naphthenic acid extracted from oil sand and to identify the isomeric species.…”