Chemical tracers for Wildfires-Analysis of runoff surface Water by LC/Q-TOF-MS.

A quantitative methodology using high resolution mass spectrometry was developed for the identification of organic compounds derived from wildfires in surface water samples. The methodology involves the use of solid-phase extraction (SPE) followed by detection using liquid chromatography-quadrupole time of flight-mass spectrometry (LC/Q-TOF-MS) for a group of fourteen chemical compounds (pyridine, benzene, naphthalene and biphenyl polycarboxylic acids). All compounds were successfully separated chromatographically using a reversed phase column and they were identified by accurate mass using the deprotonated species and their main fragment ions.

Wildfires: Identification of a new suite of aromatic polycarboxylic acids in ash and surface water.

Ash and surface water samples collected after wildfires in four different geographical locations (California, Colorado, Kansas and Alberta) were analyzed. The ash samples were leached with deionized water, and leachates were concentrated by solid phase extraction and analyzed by liquid chromatography/time-of-flight mass spectrometry. In addition, three surface water samples and a lysimeter water sample were collected from watersheds recently affected by fire in California and Colorado, and analyzed in similar fashion.

Sustainable microalgae-based technology for biotransformation of benzalkonium chloride in oil and gas produced water: A laboratory-scale study.

Many countries have implemented stringent regulatory standards for discharging produced water (PW) from the oil and gas extraction process. Among the different chemical pollutants occurring in PW, surfactants are widely applied in the oil and gas industry to provide a barrier from metal corrosion. However, the release of these substances from the shale formation can pose serious hazardous impacts on the aquatic environment.

Determination of dextromethorphan and dextrorphan solar photo-transformation products by LC/Q-TOF-MS: Laboratory scale experiments and real water samples analysis.

This work discusses the identification of the transformation products (TPs) generated during the photolytic degradation of dextromethorphan (DXM) and its metabolite dextrorphan (DXO), under simulated solar radiation in aqueous solutions (Milli-Q water and river water) in order to determinate its behavior into the aquatic environment. Tentative identification of the TPs was performed by liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/QTOF-MS), following a suspect screening approach. The use of high resolution-mass spectrometry (HRMS) allowed the tentative identification of DXM and DXO photoproducts based on the structure proposed by an in silico software, the accurate mass measurement, the MS/MS fragmentation pattern and the molecular formula finding.

Desalting and Concentration of Common Hydraulic Fracturing Fluid Additives and their Metabolites with Solid-Phase Extraction.

This work describes the development of a solid-phase extraction method capable of detecting common fracturing fluid additives in flowback and produced water with mass spectrometry. Dissolved organic carbon (DOC) was used as a bulk measurement to investigate the retentive capacity of seven sorbents and to determine a loading volume. Conductivity was used to determine rinse volume.