Search

Produced water (PW), a waste byproduct of oil and gas extraction, is a complex mixture containing numerous organic solubles and elemental species; these constituents range from polycyclic aromatic hydrocarbons to naturally occurring radioactive materials. Identification of these compounds is critical in developing reuse and disposal protocols to minimize environmental contamination and health risks. In this study, versatile extraction methodologies were investigated for the untargeted analysis of PW. Thin-film solid-phase microextraction with hydrophilic-lipophilic balance particles was utilized for the extraction of organic solubles from eight PW samples from the Permian Basin and Eagle Ford formation in Texas. Gas chromatography-mass spectrometry analysis found a total of 266 different organic constituents including 1,4-dioxane, atrazine, pyridine, and PAHs. The elemental composition of PW was evaluated using dispersive solid-phase extraction followed by inductively coupled plasma-mass spectrometry, utilizing a new coordinating sorbent, poly(pyrrole-1-carboxylic acid). This confirmed the presence of 29 elements including rare earth elements, as well as hazardous metals such as Cr, Cd, Pb, and U. Utilizing chemometric analysis, both approaches facilitated the discrimination of each PW sample based on their geochemical origin with a prediction accuracy above 90% using partial least-squares-discriminant analysis, paving the way for PW origin tracing in the environment.

Nicotinic acid adenine dinucleotide phosphate (NAADP) is a potent Ca(2+) mobilizing second messenger which triggers Ca(2+) release in both sea urchin egg homogenates and in mammalian cells. The NAADP binding protein has not been identified and the regulation of NAADP mediated Ca(2+) release remains controversial. To address this issue, we have synthesized an NAADP analog in which 3-azido-5-azidomethylbenzoic acid is attached to the amino group of 5-(3-aminopropyl)-NAADP to produce an NAADP analog which is both a photoaffinity label and clickable. This ‘all-in-one-clickable’ NAADP (AIOC-NAADP) elicited Ca(2+) release when microinjected into cultured human SKBR3 cells at low concentrations. In contrast, it displayed little activity in sea urchin egg homogenates where very high concentrations were required to elicit Ca(2+) release. In mammalian cell homogenates, incubation with low concentrations of [(32)P]AIOC-NAADP followed by irradiation with UV light resulted in labeling 23 kDa protein(s). Competition between [(32)P]AIOC-NAADP and increasing concentrations of NAADP demonstrated that the labeling was selective. We show that this label recognizes and selectively photodervatizes the 23 kDa NAADP binding protein(s) in cultured human cells identified in previous studies using [(32)P]5-N(3)-NAADP.