Question

What are masking and demasking agents in analytical chemistry?

Answer 1

Masking agent:

• During chemical analysis, a reagent that reacts with a chemical species which is capable of interfering with the chemical analysis is known as a masking agent.
• The masking agent removes the impurities from the chemical reaction.
• Example: EDTA (Ethylenediamine tetraacetic acid) serves as a masking agent in Spectrophotometric Determination of Copper with Triethylenetetramine.

Demasking agent:

• Demasking is the process in which the masked substance retains its ability to enter into a particular reaction.
• The demasking agent removes the masked substances back into the mixture.
• Example: For the selective demasking of aluminum, triethanolamine is added which also reacts with iron.