Method development for optimizing analysis of ignitable liquid residues using flow-modulated comprehensive two-dimensional gas chromatography.

The abundance and composition of matrix compounds in fire debris samples undergoing ignitable liquid residue analysis frequently leads to inconclusive results, which can be diminished by applying comprehensive two-dimensional gas chromatography (GC × GC). Method development must be undertaken to fully utilize the potential of GC × GC by maximizing separation space and resolution..

Development of retention time indices for comprehensive multidimensional gas chromatography and application to ignitable liquid residue mapping in wildfire investigations.

In this study, we introduce a simple three-step workflow for a universally applicable RI system, to be used in GC×GC analysis of ignitable liquid residue (ILR) for arson investigations. The proposed RI system applies a combination of two well-established GC RI systems: non-isothermal Kovats (K) index in the first dimension and Lee (L) index in the second dimension. The proposed KLI RI system showed very good correlations when compared with predicted values and existing RI systems (r = 0.

The application of comprehensive two-dimensional gas chromatography to the analysis of wildfire debris for ignitable liquid residue.

Arsonous wildfires are complex investigations due to the high abundance of natural background compounds and subsequent pyrolysis by-products formed during combustion. These interfering compounds can be present in large concentrations and overwhelm the marker compounds used to identify ignitable liquid residue (ILR). Complex matrix effects often interfere with the identification of ILR, providing ambiguous results.

Background levels of dioxin-like polychlorinated biphenyls (dlPCBs), polychlorinated, polybrominated and mixed halogenated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, PBDD/Fs & PXDD/Fs) in sera of pregnant women in Accra, Ghana.

Human exposure data on dioxins and dioxin-like compounds (DLCs) in Ghana are limited. Based on health risks associated with dioxins and DLCs, the impact of maternal body burdens on foetal exposure is significant. This is the first study that assesses polychlorinated, polybrominated and mixed halogenated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, PBDD/Fs and PXDD/Fs), and dioxin-like polychlorinated biphenyls (dlPCBs) in sera of primiparous Ghanaians.

Forensic source attribution for toluene in environmental samples.

The formation of toluene by microbiological processes can confound environmental investigations relating to petroleum releases. This is because toluene is a constituent of petroleum and can move readily within wetland environments, and analysis for toluene in relation to a petroleum release can lead to incorrect assignment of detected biogenic toluene as related to the release. No legally defensible method of distinguishing biogenic and petrogenic origins of detectible concentrations of toluene have been demonstrated to date.

Paraben levels in an urban community of Western Canada.

With effective antibacterial and antifungal properties, commercially used parabens are synthetic compounds widely utilized as preservatives in cosmetics, personal care products, pharmaceuticals, and as an additive in some foodstuffs. While long regarded as relatively safe and nontoxic, recent research has demonstrated xenoestrogenic properties of anthropogenic parabens with early evidence that paraben exposure may be linked to breast cancer, thyroid dysfunction, allergy, and obesity. In an attempt to determine the prevalence of paraben exposure in a Canadian urban community, a sample of convenience was done by measuring urinary levels of methyl, ethyl, propyl, butyl, and isobutyl parabens (MP, EP, PP, BP, and IP) in 39 consecutive patients in an Alberta primary care clinic.

Polyhalogenated aromatic hydrocarbons and metabolites: Relation to circulating thyroid hormone and retinol in nestling bald eagles (Haliaeetus leucocephalus).

Polyhalogenated aromatic hydrocarbons are global contaminants that are often considered to be endocrine disruptors and include 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (p,p'-DDE), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). The present study examined these compounds and their hydroxylated metabolites or analogues and relationships with circulating thyroid hormones and retinols in plasma from nestling and adult bald eagles in British Columbia, Canada, and California, USA. We also compared our results with published data.