Flowback and produced water from hydraulic fracturing contains a variety of unique organic compounds that could be used as a “fingerprint” to trace sources of future environmental contamination. This work details a new fingerprinting method employing solid phase extraction (SPE) to isolate and concentrate a hydrophobic fraction of dissolved organic carbon (DOC) from samples of hydraulic fracturing flowback and produced waters from the Denver-Julesburg Basin in northeast Colorado and the Anadarko Basin in Oklahoma. The method works on both low and high DOC concentrations. Seven SPE cartridges were evaluated for DOC breakthrough. From the breakthrough, cartridges were selected that have ideal retention characteristics for further use in isolating the hydrophobic fraction of hydraulic fracturing fluids (i.e. C-18, HLB, and PPL cartridges). After isolation and concentration, an ultrahigh pressure liquid chromatography (UHPLC) method with liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/Q-TOF/MS) was used to identify polyethylene glycols (PEGs) and polypropylene glycols (PPGs) from the recovered fraction, the parent compounds of which are used to increase viscosity of hydraulic fracturing fluids. SPE provides the additional benefit of desalting the isolate, which is vital to obtaining high quality mass spectra and compound identification. This benefit enabled the detection and identification of compounds that were previously suppressed by high salt concentrations, thus reducing the potential for a false-negative result. Finally, this method is also applied to groundwater samples thought to be influenced by flowback and produced water as a means of increasing detection limits 100x over direct analysis of raw water.

Isolation, analysis, and fingerprinting of organic compounds from hydraulic fracturing fluids using solid phase extraction and liquid chromatography mass spectrometry

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.