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Using GC × GC-FID profiles to estimate the age of weathered gasoline samples


, : Using GC × GC-FID profiles to estimate the age of weathered gasoline samples. Analytical and Bioanalytical Chemistry 401(8): 2423-2431

Predicting the amount of time that a petroleum mixture has been exposed to weathering effects has applications in areas of environmental and other forensic investigations, such as aiding in determining the cause and intent of a fire. Historically, research on the evaporation rates of hydrocarbon mixtures has focused on forensic oil spill identification and predicting if a fresh sample could be weathered to give an observed composition in an aged sample. Relatively little attention has focused on approaching the problem from the other direction: estimating exposure time based on the observed composition of a weathered sample at a given time and assuming a prior composition. Here, we build upon our previous research into the weathering of model mixtures by extending our work to gasoline. Samples of gasoline with varying octane ratings and from several vendors were weathered under controlled conditions and their composition monitored over time by two-dimensional gas chromatography (GC × GC). A variety of chemometric models were explored, including partial least squares (PLS), nonlinear PLS (PolyPLS) and locally weighted regression (LWR). A hierarchical application of multivariate techniques was able to predict the time for which a sample had been exposed to evaporative weathering. Partial least squares discriminant analysis could predict whether a sample was relatively fresh (<12 h exposure time) or highly weathered (>20 h exposure time). Subsequent regression models for these classes were evaluated for accuracy using the root mean square error of prediction. LWR was the most successful, whereby fresh and highly weathered samples were predicted to within 30 min and 5 h of exposure, respectively.

US$19.90

PMID: 21643854

DOI: 10.1007/s00216-011-5130-0


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Koltyn, K.F.; Trine, M.R.; Stegner, A.J.; Tobar, D.A., 2001: Effect of isometric exercise on pain perception and blood pressure in men and women. Purpose: To examine the influence of isometric handgrip exercise (ISO EX) on pain perception and blood pressure in men and women. Methods: Fifteen men and 16 women completed max and submax ISO EX consisting of squeezing a hand dynamometer with the...

Henderson C.R., 1980: Simple method for unbiased estimation of variance components in the mixed model. Journal of Animal Science 51(SUPPL 1): 119

Reinecke, K.P., 1981: Definitive tooth position of 22, 25, 23, 26 and 27 in combination with hypodontia 14, 24 and progenia. Stomatologie der Ddr 31(1): 39-40

Russell, F.W., 1915: A remarkable abdo minal structure in certain moths. Entomological News Philadelphia, 26 166-170

Shaw, N.S.; Liou, G.I.; Noy, N., 1998: Localization of the retinoid binding sites of human interphotoreceptor retinoid binding protein expressed in E coli. IOVS 39(4): S40, March 15

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Greene, J., 1992: Ratings cut on 8 Pa. hospitals. Modern Healthcare 22(13): 20-20

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