Classifying Separation Techniques: Separations Based on Complexation Reactions (Masking)

 Separations Based on Complexation Reactions (Masking)

One of the most widely used techniques for preventing an interference is to bind the interferent as a soluble complex, preventing it from interfering in the analyte’s deter- mination. This process is known as masking. 

Technically, masking is not a separation technique because the analyte and interferent are never physically separated from each other. Masking can, however, be considered a pseudo-separation technique, and is in- cluded here for that reason. A wide variety of ions and molecules have been used as masking agents (Table 7.6), and, as a result, selectivity is usually not a problem.



As shown in Example 7.13, a masking agent’s effectiveness can be judged by considering the equilibrium constants for the analytical and masking reactions.

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