Titration analysis method-coordination titration method (3)

4.

In actual water samples, there are often multiple metal ions coexisting, and EDTA can form stable complexes with many metal ions.

(1) pH value to control

[Example 2.

Solution: lgK _FeY = 25.

(2) Masking technology

1) Coordination masking

In selecting an amount to be considered masking agents, pH range of masking agent, the stability of the complex formed, the masking agent is added to affect the primary ion complexes thereof, and the like colors

2) Precipitation masking

The precipitation masking method requires that the solubility of the resulting precipitate is small, the reaction is safe, and it is a colorless and compact crystalline precipitate, otherwise the measured ion will be adsorbed, which will affect the observation of the color of the end point

3) Redox masking

Commonly used masking agents are listed in Table 2.

Table 2.

Related Links: Titration Analysis Method-Coordination Titration Method (2)