Principal Components Analysis and Receptor Models in Environmental Forensics

Johnson, Glenn W.; Ehrlich, Robert; Full, William E.; Ramos, Scott

doi:10.1016/b978-0-12-404696-2.00018-7

Cited by 36 publications

(43 citation statements)

References 62 publications

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“…Second, environmental forensic studies rely upon comparisons between PAH assemblages in candidate source and release area samples, which rely primarily on measurement precision and less on accuracy (9,24,26,27). Thus, so long as the PAHs in potential source materials and impacted soils and sediments are analyzed precisely (see below), their comparisons are still appropriate, i.e., absolute concentrations of the alkylated PAHs are not necessary, even when sophisticated numerical analyses are performed (31). Using history as our guide, it is expected that forensic laboratories will continue to further improve the measurement accuracy and precision in the years to come.…”

Section: Quantification Using Adopted Response Factorsmentioning

confidence: 95%

Beyond 16 Priority Pollutant PAHs: A Review of PACs used in Environmental Forensic Chemistry

Stout¹,

Emsbo-Mattingly²,

Douglas³

et al. 2015

Polycyclic Aromatic Compounds

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Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in soils and sediments, particularly in urbanized environments in which the concentrations of 16 (or so) PAHs are regulated. Distinguishing among the numerous PAH sources is of practical and legal concern and thereby is often an objective of environmental forensic chemistry studies. Studies of prospective sources and impacted soils and sediments that rely upon the 16 U.S. EPA Priority Pollutant PAHs are disadvantaged, as these few compounds generally lack the specificity to distinguish among different PAH sources in the environment. Advances in analytical and interpretive methods over several decades have shown that different PAH sources can be more defensibly distinguished using modified EPA Method 8270 that, among other improvements, measure many other polycyclic aromatic compounds (PACs) that co-occur with the Priority Pollutant PAHs in different sources and in the environment. The PACs include variously-alkylated PAHs and polycyclic aromatic sulfur heterocyclics (PASHs) homologs and individual isomers, which are herein reviewed. Collectively, these PACs provide a higher degree of specificity among PAC sources and can be used to understand the effects of weathering on PAH assemblages. Despite their diagnostic capacity, PACs should not be relied upon at the exclusion of other compound groups (e.g., petroleum biomarkers) in most environmental forensic chemistry studies. In light of these advances, source characterization studies that rely only upon the 16 (or so) Priority Pollutant PAHs warrant considerable caution.

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Section: Quantification Using Adopted Response Factorsmentioning

confidence: 95%

Beyond 16 Priority Pollutant PAHs: A Review of PACs used in Environmental Forensic Chemistry

Stout¹,

Emsbo-Mattingly²,

Douglas³

et al. 2015

Polycyclic Aromatic Compounds

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“…[64] The experimental conditions were the same as those used to follow the heme coordination. The experimental data were processed by ap rincipal component analysis [65] to decompose each data set into its orthogonal components. The covariance matrix was built from spectra recorded at different temperatures, and then diagonalized using the MATLAB software package (MATLAB R2010b, MathWorks, Inc.).…”

Section: Circular Dichroism Spectroscopymentioning

confidence: 99%

Mimicking Tyrosine Phosphorylation in Human Cytochrome c by the Evolved tRNA Synthetase Technique

Guerra‐Castellano

Díaz‐Quintana

Moreno‐Beltrán

et al. 2015

Chemistry A European J

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Phosphorylation of tyrosine 48 of cytochrome c is related to a wide range of human diseases due to the pleiotropic role of the heme-protein in cell life and death. However, the structural conformation and physicochemical properties of phosphorylated cytochrome c are difficult to study as its yield from cell extracts is very low and its kinase remains unknown. Herein, we report a high-yielding synthesis of a close mimic of phosphorylated cytochrome c, developed by optimization of the synthesis of the non-canonical amino acid p-carboxymethyl-L-phenylalanine (pCMF) and its efficient site-specific incorporation at position 48. It is noteworthy that the Y48pCMF mutation significantly destabilizes the Fe-Met bond in the ferric form of cytochrome c, thereby lowering the pKa value for the alkaline transition of the heme-protein. This finding reveals the differential ability of the phosphomimic protein to drive certain events. This modified cytochrome c might be an important tool to investigate the role of the natural protein following phosphorylation.

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“…Instead, PVA derives estimates of endmember compositions from the data set itself. A complete description and literature review of the methodology can be found in Johnson et al (2007). The PVA method involves mathematically fitting an n-dimensional polytope around a cloud of normalized data.…”

Section: Unmixing Evaluationmentioning

confidence: 99%

“…The exploratory data analysis method used in this study is Polytopic Vector Analysis (PVA) (Full et al, 1981(Full et al, , 1982Johnson et al, 2007) which is coded into the program SAWVEC. This method has been used in a variety of geologic and environmental chemical studies, including petroleum geochemistry (Collister et al, 2004).…”

Section: Unmixing Evaluationmentioning

confidence: 99%

Egypt far Western Desert basins petroleum charge system as defined by oil chemistry and unmixing analysis

Abrams¹,

Greb²,

Collister

et al. 2016

Marine and Petroleum Geology

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Principal Components Analysis and Receptor Models in Environmental Forensics

Cited by 36 publications

References 62 publications

Beyond 16 Priority Pollutant PAHs: A Review of PACs used in Environmental Forensic Chemistry

Beyond 16 Priority Pollutant PAHs: A Review of PACs used in Environmental Forensic Chemistry

Mimicking Tyrosine Phosphorylation in Human Cytochrome c by the Evolved tRNA Synthetase Technique

Egypt far Western Desert basins petroleum charge system as defined by oil chemistry and unmixing analysis

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