Department of Chemistry, School of Chemistry, Food and Pharmacy, Whiteknights Campus, University of Reading, Reading, UK.
BP Technology centre, Pangbourne, UK.
Rapid Commun Mass Spectrom. 2022 Jul 30;36(14):e9320. doi: 10.1002/rcm.9320.
Fully formulated oils (FFOs) are integral to automotive lubrication; however, detailed compositional analysis is challenging due to high levels of chemical complexity. In particular, existing mass spectrometric approaches often target particular FFO components, leading to poor analytical coverage of the overall formulation, with increased overheads and analytical timescales.
Herein we report the application of a commercially available SICRIT SC-20 dielectric barrier discharge ionisation (DBDI) source and Thermo Fisher Scientific LTQ Orbitrap XL to the analysis of an FFO. Nitrogen was used as a discharge gas for the DBDI source, and was modified using a range of commonplace solvents to tailor the experimental conditions for the analysis of various components.
The reported method allowed analysis of a range of FFO components of interest, encompassing a wide range of chemistries, in under 1 min. By modifying the discharge gas used for ionisation, experiments could be optimised for the analysis of particular FFO components across positive and negative ion modes. In particular, use of water vapour as a discharge gas modifier with positive ion mode mass spectrometry permitted concomitant analysis of antioxidants and base oil hydrocarbons. Furthermore, case studies of selected linear alkanes and alkenes profile the differences in the range of ions formed across these saturated and unsaturated aliphatic compounds, giving insight into the fate of base oil hydrocarbons in FFO analyses.
A rapid method for analysis of FFO compositions has been developed and provides coverage of a range of components of interest. The results indicate that the method presented may be of utility in analysis of other FFOs or similarly challenging complex mixtures.
全配方油（FFO）是汽车润滑的重要组成部分；然而，由于化学复杂性高，详细的成分分析具有挑战性。特别是，现有的质谱分析方法通常针对特定的 FFO 成分，导致整体配方的分析覆盖率较差，分析开销和时间尺度增加。
本文报告了商业可用的 SICRIT SC-20 介电阻挡放电电离（DBDI）源和 Thermo Fisher Scientific LTQ Orbitrap XL 在 FFO 分析中的应用。氮气用作 DBDI 源的放电气体，并使用一系列常见溶剂进行修饰，以调整实验条件以分析各种成分。
所报道的方法允许在不到 1 分钟的时间内分析一系列感兴趣的 FFO 成分，涵盖了广泛的化学物质。通过修饰用于离子化的放电气体，可以针对正离子和负离子模式下的特定 FFO 成分优化实验。特别是，在正离子模式质谱中使用水蒸气作为放电气体修饰剂，可以同时分析抗氧化剂和基础油烃。此外，对选定的直链烷烃和烯烃的案例研究描绘了这些饱和和不饱和脂肪族化合物中形成的离子范围的差异，深入了解了基础油烃在 FFO 分析中的命运。
已经开发出一种快速分析 FFO 成分的方法，提供了一系列感兴趣成分的覆盖范围。结果表明，所提出的方法可能对其他 FFO 或类似具有挑战性的复杂混合物的分析有用。
