Detection of Residual Oil-Sand-Derived Organic Material in Developing Soils of Reclamation Sites by Ultra-High-Resolution Mass Spectrometry

Abstract

The reconstruction of disturbed landscapes back to working ecosystems is an issue of increasing importance for the oil sand areas in Alberta, Canada. In this context, the fate of oil-sand-derived organic material in the tailings sands used for reclamation is of utmost environmental importance. Here we use electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry of maltene fractions to identify compositional variations over a complete oil sand mining and recultivation process chain. On the basis of bulk compound class distributions and percentages of unique elemental compositions, we identify specific compositional features that are related to the different steps of the process chain. The double bond equivalent and carbon number distributions of the N1 and S1O2 classes are almost invariant along the process chain, despite a significant decrease in overall abundance. We thus suggest that these oil-sand-derived components can be used as sensitive tracers of residual bitumen, even in soils from relatively old reclamation sites. The patterns of the O2, O3, and O4 classes may be applied to assess process-chain-related changes in organic matter composition, including the formation of plant-derived soil organic matter on the reclamation sites. The N1O2 species appear to be related to unidentified processes in the tailings ponds but do not represent products of aerobic biodegradation of pyrrolic nitrogen compounds.

Development of a Non-Targeted Method to Study Petroleum Polyaromatic Hydrocarbons in Soil by Ultrahigh Resolution Mass Spectrometry Using Multiple Ionization Methods

“…C 30 H 40 and C 27 H 44 S with a double bond equivalent (DBE) of 11 and 6 were the first and second highest signal detected in the mass spectra for the original crude oil, Soxhlet and SFE extracts. By decreasing m/z value the DBE value of isobaric pure hydrocarbon ions (C 29 Figure 3), which have a Dm ¼ 0.09390 Da between each other, increases from 4 to 25. The extraction efficiency of SFE decreases the higher the aromaticity is.…”

“…21 Negative mode ESI coupled to FT MS opens the possibility for detailed characterization of acidic compounds especially oxygenated classes. This combination is already applied for the analysis of naphtenic acids from environmental samples, [22][23][24] natural organic matter (NOM), [25][26][27][28] oil-sand-derived organic material, 29 and soil organic matters (SOM). [30][31][32] In contrast to these, basic compounds for instance pyridine-containing molecules are favored under positive mode ESI.…”

NSO-compounds in oil-bearing fluid inclusions revealed by FT-ICR-MS in APPI (+) and ESI (−) modes: A new method development

“…Importantly, the FI oils can also be used to search for early indications of oil biodegradation. Oxygen compounds, especially O1 and O2 compounds, measured by the ESI (-) mode have been widely studied and relationships between those compound class compositions and biodegradation have been demonstrated (Kim et al, 2005;Liao et al, 2012;Noah et al, 2015;Martins et al, 2017). It is known from previous ESI FT-ICR-MS based investigations of crude oils, that the abundance of O2 species increase while those of the O1 species decrease with increasing level of biodegradation (Kim et al, 2005;Hughey et al, 2007).…”

“…O2 compounds are abundant, especially those from DBE 1 class representing acyclic carboxylic acids (Kim et al, 2005). In contrast, O2 compounds with DBE 2, 3 and 4 represent mono-, bi-and tricyclic naphthenic acids (Kim et al, 2005;Noah et al, 2015). Kim et al (2005) introduced the A/C (acyclic/cyclic) ratio (A/C = ∑O2, DBE1/∑O2, DBE2+3+4) to estimate potential biodegradation levels of crude oil.…”

Functioning of reclaimed oil sands ecosystems and the implications for reclamation certification

“…Other key reclamation issues in the AOSR include establishing adequate nutrient supplies for plants (Quideau et al, 2013;Jung et al, 2014) and avoiding an accumulation of sodium salts and residual hydrocarbons in plants and soil (Noah et al, 2015;Kessel et al, 2018). These issues are linked to a number of proposed indicators including soil salinity, ecosystem NPP, ecosystem health, and resilience, among others (Table 5-1).…”