Evaluation of Environmental Samples Containing Heavy Hydrocarbon Components in Environmental Forensic Investigations
This article presents a procedure to evaluate and characterize environmental samples containing mixtures of hydrocarbons over a wide boiling range of materials that include fuels and other products used in commerce. The range of the method extends to the higher boiling and heavier molecular weight hydrocarbon products in the range of motor oil, bunker fuel, and heavier residue materials. The procedure uses the analytical laboratory technique of high-temperature simulated distillation along with
... illation along with mathematical regression of the analytical data to estimate the relative contribution of individual products in mixtures of hydrocarbons present in environmental samples. An analytical technique to determine hydrocarbon-type distributions by gas chromatography-mass spectrometry with nitric oxide ionization spectrometry evaluation is also presented. This type of analysis allows complex hydrocarbon mixtures to be classified by their chemical composition, or types of hydrocarbons that include paraffins, cycloparaffins, monoaromatics, and polycyclic aromatic hydrocarbons. Characteristic hydrocarbon patterns-for example, in the relative distribution of polycyclic aromatic hydrocarbons-are valuable for determining the potential origin of materials present in environmental samples. These methods provide quantitative data for hydrocarbon components in mixtures as a function of boiling range and "hydrocarbon fingerprints" of the types of materials present. This information is valuable in assessing environmental impacts of hydrocarbons at contaminated sites and establishing the liabilities and cost allocations for responsible parties.