Characterization of naphthenic acids using mass spectroscopy and chromatographic techniques: study of technical mixtures

Damasceno, Flaviana Cardoso; Gruber, Leonardo; Geller, Ana Maria; Campos, Maria Cecı́lia Vaz de; Gomes, Alexandre O.; Guimarães, Regina C. L.; Péres, Valéria Flores; Jacques, Rosângela Assis; Caramão, Elina Bastos

doi:10.1039/c3ay40851e

Cited by 37 publications

(28 citation statements)

References 47 publications

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“…Based on the detected peak areas, the most abundant single O2NA species in this technical mixture was C 19 H 38 O 2 , a saturated fatty acid with an odd number of carbon atoms. This observation is in agreement with a previous study in which GC‐MS and infusion‐ESI/MS were used for profiling O2NAs in two NA technical mixtures including the one from Sigma . For the Merichem NA technical mixture analyzed in this work, the hydrogen deficiency ranged from z = 0 to −24 and the n ranged from 5 to 38 for z = 0 and from 23 to 26 for z = −24.…”

Section: Resultssupporting

confidence: 91%

Molecular profiling of naphthenic acids in technical mixtures and oil sands process‐affected water using polar reversed‐phase liquid chromatography–mass spectrometry

Han

Lin

et al. 2016

Electrophoresis

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In this work, a reversed-phase ultra-HPLC (UHPLC) ultrahigh resolution MS (UHRMS) method was evaluated for the comprehensive profiling of NAs containing two O atoms in each molecule (O2NAs; general formula C H O , where n is the number of carbon atoms and z represents hydrogen deficiency). Using a polar cyanopropyl-bonded phase column and negative-ion electrospray ionization mass spectrometric detection at 120,000 FWHM (m/z 400), 187 and 226 O2NA species were found in two naphthenic acid technical mixtures, and 424 and 198 species with molecular formulas corresponding to O2NAs were found in two oil sands process-affected water samples (one from a surface mining operation and the other from a steam-assisted gravity drainage operation), respectively. To our knowledge, these are the highest numbers of molecular compositions of O2NAs that have been profiled thus far in environmental samples. Assignments were based on accurate mass measurements (≤3 ppm) combined with rational molecular formula generation, correlation of chromatographic behavior of O2NA homologues with their elemental compositions, and confirmation with carboxyl group-specific chemical derivatization using 3-nitrophenylhydrazine. Application of this UHPLC-UHRMS method to the quantitation of O2NAs in the surface mining operation-derived water sample showed excellent linearity (R = 0.9999) with external calibration, a linear range of 256-fold in concentration, and quantitation accuracies of 64.9 and 69.4% at two "standard substance" spiking levels.

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Section: Resultssupporting

confidence: 91%

Molecular profiling of naphthenic acids in technical mixtures and oil sands process‐affected water using polar reversed‐phase liquid chromatography–mass spectrometry

Han

Lin

et al. 2016

Electrophoresis

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“…Furthermore, the few bicyclic acids identified in commercial naphthenic acids to date represent only a small fraction of those actually present, as the >100 compounds revealed by comprehensive multidimensional gas chromatography-mass spectrometry of the methyl esters (GCxGC-MS) of two commercial naphthenic acids mixtures attests [18].…”

Section: Accepted By J Chromatogr Amentioning

confidence: 99%

“…Recently Damasceno et al [18] analysed two commercial acid mixtures by GCxGC-MS, characterising groups of naphthenic acids by their 'z' value (i.e. hydrogen deficiency attributed to the number of rings).…”

Section: Accepted By J Chromatogr Amentioning

confidence: 99%

Bicyclic naphthenic acids in oil sands process water: Identification by comprehensive multidimensional gas chromatography–mass spectrometry

Wilde

West

Scarlett

et al. 2015

Journal of Chromatography A

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Although bicyclic acids have been reported to be the major naphthenic acids in oil sands process-affected water (OSPW) and a well-accepted screening assay indicated that some bicyclics were the most acutely toxic acids tested, none have yet been identified. Here we show by comprehensive multidimensional gas chromatography-mass spectrometry (GC×GC-MS), that >100 C8-15 bicyclic acids are typically present in OSPW. Synthesis or purchase allowed us to establish the GC×GC retention times of methyl esters of numerous of these and the mass spectra and published spectra of some additional types, allowed us to identify bicyclo[2.2.1]heptane, bicyclo[3.2.1]octane, bicyclo[4.3.0]nonane, bicyclo[3.3.1]nonane and bicyclo[4.4.0]decane acids in OSPW and a bicyclo[2.2.2]octane acid in a commercial acid mixture. The retention positions of authentic bicyclo[3.3.0]octane and bicyclo[4.2.0]octane carboxylic acid methyl esters and published retention indices, showed these were also possibilities, as were bicyclo[3.1.1]heptane acids. Bicyclo[5.3.0]decane and cyclopentylcyclopentane carboxylic acids were ruled out in the samples analysed, on the basis that the corresponding alkanes eluted well after bicyclo[4.4.0]decane (latest eluting acids). Bicyclo[4.2.1]nonane, bicyclo[3.2.2]nonane, bicyclo[3.3.2]decane, bicyclo[4.2.2]decane and spiro[4.5]decane carboxylic acids could not be ruled out or in, as no authentic compounds or literature data were available. Mass spectra of the methyl esters of the higher bicyclic C12-15 acids suggested that many were simply analogues of the acids identified above, with longer alkanoate chains and/or alkyl substituents. Our hypothesis is that these acids represent the biotransformation products of the initially somewhat more bio-resistant bicyclanes of petroleum. Although remediation studies suggest that many bicyclic acids can be relatively quickly removed from suitably treated OSPW, examination by GC×GC-MS may show which isomers are affected most. Knowledge of the structures will allow the toxicity of any residual isomers to be calculated and measured.

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“…A commercial mixture of naphthenic acids (technical grade, carbon numbers 6-20, z-classes 0 to −4, as characterized by Damasceno et al [15]), dichloromethane (DCM, ≥99.9%, HPLC grade) NaOH (≥98%, ACS grade) and nitric acid (70%, ACS grade) were purchased from Sigma-Aldrich (St. Louis, MO, USA) and used as received. Sulfuric acid (95-98%, ACS grade, Fisher, Hampton, NH, USA) and titanium dioxide nanoparticles (Aeroxide P25,~10-50 nm particle diameter, 55 m 2 g −1 surface area, Acros, Geel, Belgium) were used as received.…”

Section: Methodsmentioning

confidence: 99%

Floating Photocatalysts for Passive Solar Degradation of Naphthenic Acids in Oil Sands Process-Affected Water

Leshuk

Krishnakumar

Livera

et al. 2018

Water

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Abstract:Oil sands process-affected water (OSPW), generated from bitumen extraction in the Canadian oil sands, may require treatment to enable safe discharge to receiving watersheds, as dissolved naphthenic acids (NAs) and other acid extractable organics (AEO), identified as the primary toxic components of OSPW, are environmentally persistent and poorly biodegradable. However, conventional advanced oxidation processes (AOPs) are impractically expensive to treat the volumes of OSPW stockpiled in the Athabasca region. Here we prepared floating photocatalysts (FPCs) by immobilizing TiO 2 on glass microbubbles, such that the composite particles float at the air-water interface for passive solar photocatalysis. The FPCs were demonstrated to outperform P25 TiO 2 nanoparticles in degrading AEO in raw OSPW under natural sunlight and gentle mixing conditions. The FPCs were also found to be recyclable for multiple uses through simple flotation and skimming. This paper thus demonstrates the concept of a fully passive AOP that may be scalable to oil sands water treatment challenges, achieving efficient NA reduction solely through the energy provided by sunlight and natural mixing processes (wind and waves).

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Characterization of naphthenic acids using mass spectroscopy and chromatographic techniques: study of technical mixtures

Cited by 37 publications

References 47 publications

Molecular profiling of naphthenic acids in technical mixtures and oil sands process‐affected water using polar reversed‐phase liquid chromatography–mass spectrometry

Molecular profiling of naphthenic acids in technical mixtures and oil sands process‐affected water using polar reversed‐phase liquid chromatography–mass spectrometry

Bicyclic naphthenic acids in oil sands process water: Identification by comprehensive multidimensional gas chromatography–mass spectrometry

Floating Photocatalysts for Passive Solar Degradation of Naphthenic Acids in Oil Sands Process-Affected Water

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