« Previous AbstractStructure-activity relationship observations for the bagworm moth pheromone    Next Abstract"Orientation of colonized sand flies Phlebotomus papatasi, P. duboscqi, and Lutzomyia longipalpis (Diptera: Psychodidae) to diverse honeys using a 3-chamber in-line olfactometer" »

J Chromatogr A

Title:		Use of carbon isotopic ratios in nontargeted analysis to screen for anthropogenic compounds in complex environmental matrices
Author(s):		Washington JW; Rosal CG; Ulrich EM; Jenkins TM;
Address:		"USEPA, National Exposure Research Laboratory, 960 College Station Road, Athens, GA, 30605, United States. Electronic address: washington.john@epa.gov. USEPA, National Exposure Research Laboratory, 944 East Harmon Avenue, Las Vegas, NV, 89119, United States. Electronic address: rosal.charlita@epa.gov. USEPA, National Exposure Research Laboratory, 109 TW Alexander Drive, Research Triangle Park, NC, 27711, United States. Senior Environmental Employee Program, USEPA, National Exposure Research Laboratory, 960 College Station Road, Athens, GA, 30605, United States"
Journal Title:		J Chromatogr A
Year:		2019
Volume:		20181111
Issue:
Page Number:		73 - 79
DOI:		10.1016/j.chroma.2018.11.013
ISSN/ISBN:		1873-3778 (Electronic) 0021-9673 (Print) 0021-9673 (Linking)
Abstract:		"Analytical data for ultra-high-performance liquid chromatography (UHPLC), nontargeted, high-resolution, mass-spectrometry (HR/MS) molecular features from a wide array of samples are used to calculate (13)C(1)(12)C((n-1))/(12)C(n) isotopologue ratios. These ratios increase with molecular carbon number roughly following a trend defined by atmospheric carbon. When the effective source reservoir (13)C/(12)C ratio is calculated from the isotopologue ratio (assuming a fractionation factor of unity), features in biotic samples uniformly are tightly grouped, proximate to atmospheric (13)C/(12)C ratio. In contrast, features in soil natural organic matter (NOM), dust NOM and anthropogenic compounds range from proximate to relatively divergent from atmospheric (13)C/(12)C. For the NOM, (13)C/(12)C ratios are consistent with an expected preferential volatilization of (12)C, rendering features in soil NOM (13)C-enriched and some features in dust NOM (13)C-depleted. Anthropogenic compounds tend to diverge most dramatically from atmospheric (13)C/(12)C, generally toward (13)C-depletion, but pesticides we tested tended toward (13)C-enriched. This pattern is robust and evident in: i) anthropogenic vs natural features in dust; ii) perfluorinated compounds in standards and as soil contaminants; and iii) sunscreen compounds in commercial products and wastewater. Considering the observed wide (13)C/(12)C range for anthropogenic compounds, we suggest Rayleigh distillation during synthetic processes commonly favors one isotope over the other, rendering a source reservoir that is progressively depleted as synthesis proceeds and, consequently, generates a wide variation in (13)C/(12)C for man-made products. However, kinetic-isotopic effects and/or synthesis from petroleum/natural gas might contribute to the anthropogenic isotopic signature as well. Regardless of cause, (13)C/(12)C can be used to cull HR/MS molecular features that are more likely to be of anthropogenic or non-biotic origin"
Keywords:		Atmosphere/chemistry Carbon/chemistry Carbon Isotopes/*analysis Dust/analysis *Environment *Human Activities Humans Soil/chemistry Volatilization Anthropogenic compounds Isotopic ratios Nontargeted analysis;
Notes:		"MedlineWashington, John W Rosal, Charlita G Ulrich, Elin M Jenkins, Thomas M eng EPA999999/ImEPA/Intramural EPA/ Netherlands 2018/11/21 J Chromatogr A. 2019 Jan 4; 1583:73-79. doi: 10.1016/j.chroma.2018.11.013. Epub 2018 Nov 11"