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Crude (4-methylcyclohexyl)methanol (MCHM) is a chemical blend, mainly used in the coal industry for the separation of usable coal from rocks, debris, and coal dust by froth flotation. Following a 2014 MCHM spill in the Elk River in West Virginia, USA, studies demonstrated that MCHM sorbed into water pipes and linings readily desorbed from polyethylene into water at levels above the odour threshold, confirming the risk of its long-term exposure from contaminated tap water pipelines. In light of this, it is imperative to develop analytical methods able to detect crude MCHM components in environmental water samples. In this work, two microextractive methods based on solid-phase microextraction (SPME) in fibre format and thin film microextraction (TFME) were developed and validated. Their performance was compared with a modified solid-phase extraction (SPE) method based on U.S. Environmental Protection Agency (EPA) Method 522 for analysis of volatiles in water. SPME and TFME methods both showed enhanced performance in terms of achievable limit of quantitation (LOQ) compared to the SPE protocol. Moreover, the sensitivity of the TFME method, coupled with its higher analytical throughput, established TFME as the optimal extraction approach for 4-MCHM and other constituents of crude MCHM, with limits of quantitation below the odour threshold for aqueous crude MCHM in 19-21 [degrees]C deionized water (0.55 [micro]g/L)., On January 9, 2014, an estimated 37,800 litres (9,986 gallons) of a chemical mixture was spilled into the Elk River upriver from Charleston, West Virginia, USA. This mixture, used in [...]

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.