Development of a Novel Mass Spectrometric ... - Jacobs University
Development of a Novel Mass Spectrometric ... - Jacobs University
Development of a Novel Mass Spectrometric ... - Jacobs University
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Introduction<br />
1.2 Presence and Fate <strong>of</strong> Hydrocarbons in Contaminated Sites<br />
Petroleum samples involve many hydrocarbon mixtures like paraffins, cyclic<br />
paraffins, condensed aromatics and various heteroatom hydrocarbons (mostly O, S<br />
and N heterocycles). 31 The classification <strong>of</strong> hydrocarbons is shown below. Original<br />
petroleum contains molecules <strong>of</strong> a wide boiling point range from highly volatile<br />
C4 hydrocarbons to non-volatile asphaltenes. Generally petroleum mixtures are<br />
common site contaminants and weathered petroleum residuals may stay bound to<br />
soils or sediments for years. 32 In part due to their complexity, little is known about<br />
detailed chemical composition and consequently their potential for health or<br />
environmental impacts. Petroleum mixtures consist primarily <strong>of</strong> relatively<br />
unreactive complex hydrocarbons covering a wide boiling point range. In many<br />
mixtures, hydrocarbons range from volatile, short-chained organic compounds to<br />
heavy, long-chained, branched compounds. The exact composition <strong>of</strong> petroleum<br />
products varies depending upon the source, the modifiers or chemical processing.<br />
In addition to that the chemical composition <strong>of</strong> the product can be further affected<br />
by weathering and/or biological modification upon release to the environment. 33<br />
On the other hand, the disposal <strong>of</strong> toxic industrial wastes through landfill,<br />
incineration or other procedures is a controversial subject, as toxic chemicals or<br />
their decomposition products may contaminate ground and drinking water or<br />
escape into the atmosphere during the production, conservation and treatment <strong>of</strong><br />
the wastes. The lack <strong>of</strong> adequate regulation and <strong>of</strong>ficial treatment and disposal<br />
plants in many countries has led to the illegal collection, transportation and<br />
dumping <strong>of</strong> wastes that, after the introduction <strong>of</strong> legislation designed to control the<br />
problem, must be recovered, identified and properly disposed <strong>of</strong>. On the other hand<br />
the analysis <strong>of</strong> the complex mixtures <strong>of</strong> industrial solvents that, being in liquid<br />
form and <strong>of</strong>ten stored in metallic drums which are subject to corrosion, may<br />
contaminate the landfill sites and could be leached by running water, or escape into<br />
the atmosphere as a result <strong>of</strong> their appreciable vapor pressures.<br />
Soil contamination has been a growing concern because it can be a source <strong>of</strong><br />
groundwater (drinking water) contamination. In addition to that contaminated soils<br />
4