Presence of organic compounds in soil

Contaminated land can be the result of direct or diffuse pollution. This may strongly affect the way contaminants are present on the site and in the soil samples to be analysed. Direct pollution, as present in a lot of industrial sites, may result in the presence of the neat contamination (e.g. tar-like particles or liquids). In diffuse polluted areas, the contaminants are more evenly distributed and are 

To isolate or extract a compound from the soil matrix the following steps are necessary  

The soil matrix has to be separated from the released compound. 

In the past the accent was on step 2 like dissolves like. Good solvents were also considered as being good extractants. Steps 1 and 3 are not set by the properties of the organic compound, but by the soil matrix. The properties of organic contaminants differ from the properties of the soil. The way contaminants are present in soil has nothing to do with like dissolves like, but more with the fact that the contaminants have less attraction to their original environmental matrices (water and air). 

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The presence of organic compounds in soil and the difficulties of extraction are extensively discussed in the chapter on SVOCs. The primary sources of VOCs in soil are from petroleum products and the industrial use of solvents... 

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