Pre-treatment in relation to extraction

Organic compounds having acidic or basic properties often need adjustment of the pH, such as described for phenols (see Section 8.6.5). It may also be possible that some organic contaminants are more easy accessible and soluble in the presence of water as described for herbicides further in this chapter. In these cases, removal of the water is not permitted and the water present is part of the extraction procedure. 

Component properties like the solubility and Kow (distribution coefficient between octanol and water) can be used in the development of extraction procedures. Table 8.1 gives a overview of some components described in this book. 

Compound Solubility in water (mg/1) Log TT ow Compound Solubility in water (mg/1) Log V XVOW 

These constants are available in Handbooks like the Pesticide Manual (Tomlin 2000) or can be found on the internet for instance on the Physprop database (http //esc.syrres.com/interkow/physdemo.htm). A good chemical entrance is www.chemfinder.com. If there are more than one isomer, figures for the most common isomers are given. 

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