Analysis of hydraulic fracturing additives by LC/Q-TOF-MS
The chemical additives used in fracturing fluids can be used as tracers of water contamination caused by hydraulic fracturing operations. For this purpose, a complete chemical characterization is necessary using advanced analytical techniques. Liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC/Q-TOF-MS) was used to identify chemical additives present in flowback and produced waters. Accurate mass measurements of main ions and fragments were used to characterize the major components of fracking fluids. Sodium adducts turned out to be the main molecular adduct ions detected for some additives due to oxygen-rich structures. Among the classes of chemical components analyzed by mass spectrometry include gels (guar gum), biocides (glutaraldehyde and alkyl dimethyl benzyl ammonium chloride), and surfactants (cocamidopropyl dimethylamines, cocamidopropyl hydroxysultaines, and cocamidopropyl derivatives). The capabilities of accurate mass and MS-MS fragmentation are explored for the unequivocal identification of these compounds. A special emphasis is given to the mass spectrometry elucidation approaches used to identify a major class of hydraulic fracturing compounds, surfactants.
KeywordsHydraulic fracturing Fracking Environmental High resolution Time-of-flight mass spectrometry Flowback waters Produced waters
We would like to thank Dr. James Rosenblum and Dr. Yaal Lester for providing the flowback and produced water samples shown in Figs. 3 and 6, respectively. The samples were obtained through the AirWaterGas Sustainability Research Network, funded by the National Science Foundation under Grant No. CBET-1240584. We also thank Agilent Technologies for instrument support.
- 1.Vidic RD, Brantley SL, Vandenbossche JM, Yoxtheimer D, Abad JD (2013) Impact of shale gas development on regional water quality. Science 340 (6134): Article Number: 1235009Google Scholar
- 14.FracFocus, FracFocus Chemical Disclosure Registry, Ground Water Pro-tection Council and Interstate Oil and Gas Compact Commission, 2013, http://fracfocus.org. Accessed Dec 2014. (2013)
- 18.Strong LC, Gould T, Kasinkas L, Sadowsky MJ, Aksan A, Wackett LP (2013) Biodegradation in produced waters: chemistry, microbiology, and engineering. Abstr Pap Am Chem Soc 246Google Scholar
- 25.Kawamura Y GUAR GUM: Chemical and technical assessment. http://www.fao.org/fileadmin/templates/agns/pdf/jecfa/cta/69/Guar_gum.pdf
- 27.McCurdy R (2011) High rate hydraulic fracturing additives in non-Marcellus unconventional shale. In: Proceedings of the technical workshops for the Hydraulic fracturing study: chemical & analytical methods, February 24–25, 2011, Arlington, VA, February; U.S. Environmental Protection Agency, 2011Google Scholar
- 31.Migneault I, Dartiguenave C, Bertrand MJ, Waldron KC (2004) Glutaraldehyde: behavior in aqueous solution, reaction with proteins, and application to enzyme crosslinking. BioTechniques 37(5):790–795Google Scholar
- 33.US House of Representatives, Committee on Energy and Commerce, 2011. Chemicals used in hydraulic fracturingGoogle Scholar