Considerations and Limitations

Solvent extraction, in combination with the use of a radioactive tracer, is an excellent tool for the determination of stabihty constants in systems where low solubihty or hydrolysis at low pH is an issue. Nevertheless, there still may be limitations since an extractant must be found that extracts the metal of interest but also binds with a strength that is suitable in comparison with the stabihty constant to be determined. Controlling experimental factors such as temperature and pH may be difficult since the extraction itself may affect, for example, the pH of the solution where, for hydrolysis reactions, the free hydrogen ion concentration is the parameter of importance. Consequently, an online system such as the AKUFVE system is likely to have clear advantages. 

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This chapter provides a summary of concepts that molecular designers should be cognizant of when trying to minimize biological activity by manipulating physical and chemical properties of chemicals. Since the most easily accessible source of property values is often computational, the second half of the chapter provides a primer in the types of considerations and limitations that have to be appreciated when obtaining predicted property values. 

Lickly, T. D., Rainey M. L. Burgert L. C., Breder C. V., Borodinsky L. 1997, Using a simple diffusion model to predict residual monomer migration - considerations and limitations. Food Additives and Cntaminants, 14. 65-74. 

PRACTICAL CONSIDERATIONS AND LIMITATIONS FOR COUPLED BIO-ELECTRO PROCESSES... 

An external antistat is applied via a carrier medium to the surface of the plastic part. The same considerations and limitations apply as with nonmigrating slip additives. Conductive filler is incorporated into the organic substrates and builds up a conductive network on a molecular level. While both approaches are used in organic substrates, they are not the most common. 

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