Zahraei Ali, Arisz Peter W F, van Bavel Alexander P, Heeren Ron M A
Maastricht MultiModal Molecular Imaging (M4I) Institute, Division of Imaging Mass Spectrometry, Maastricht University, Maastricht, The Netherlands.
Shell Global Solutions International BV, Amsterdam, The Netherlands.
Energy Fuels. 2018 Jul 19;32(7):7347-7357. doi: 10.1021/acs.energyfuels.8b00639. Epub 2018 Jun 7.
A light oil was separated into four chromatographic fractions that serve as proxy for SARA fractions. The fractions were (semi)quantified on a rod by TLC-flame ionization detection and characterized on a plate with laser desorption ionization-mass spectrometry imaging (TLC-LDI-MS). Comparisons of (semi)quantitative TLC-FID and qualitative TLC-LDI-MS results showed that LDI-MS was most sensitive for detection of molecules in the polar P1 fraction, and, to some extent, for the aromatics fraction, while no signal was observed for the most polar P2 and saturates fractions. Based on these results, limits of the compositional space, as observed by the laser ionization technique, were evaluated. The molecular speciation between and within the spots of the aromatics and the P1 fractions were analyzed and interpreted in terms of oil-SiO versus oil-solvent interactions, as a function of molecular characteristics such as DBE, aromaticity (H/C ratio), heteroatom content, degree of alkylation, and shielding of heteroatoms. In addition, the high oil loading resulted in an interesting bifurcation of the aromatics spot, which implies that oil-oil interactions can be enforced and studied in the TLC model system.
一种轻质油被分离成四个色谱馏分，用作SARA馏分的替代物。这些馏分通过薄层色谱-火焰离子化检测在棒上进行（半）定量，并通过激光解吸电离-质谱成像（TLC-LDI-MS）在板上进行表征。（半）定量薄层色谱-火焰离子化检测和定性薄层色谱-激光解吸电离-质谱结果的比较表明，激光解吸电离-质谱对极性P1馏分中的分子检测最为灵敏，在一定程度上对芳烃馏分也很灵敏，而对于极性最强的P2馏分和饱和烃馏分则未观察到信号。基于这些结果，评估了激光电离技术所观察到的组成空间的限度。根据油与二氧化硅以及油与溶剂之间的相互作用，从诸如双键当量（DBE）、芳香性（氢碳比）、杂原子含量、烷基化程度和杂原子屏蔽等分子特征方面，对芳烃和P1馏分斑点之间以及斑点内部的分子形态进行了分析和解释。此外，高油负载导致芳烃斑点出现有趣的分叉，这意味着在薄层色谱模型系统中可以加强和研究油-油相互作用。
