Kompleksometriset

Kompleksometriset titration, often referred to as complexometric titrations, are a type of chemical analysis used to determine the concentration of a specific metal ion in a solution. This method relies on the formation of a stable, soluble complex between the metal ion and a chelating agent. A chelating agent is a molecule that can bind to a metal ion at multiple points, forming a ring-like structure.

The most commonly used chelating agent in complexometric titrations is ethylenediaminetetraacetic acid, or EDTA. EDTA is a hexadentate ligand, meaning it can form six coordinate bonds with a metal ion. The reaction between the metal ion and EDTA forms a highly stable, usually colorless, complex.

During a complexometric titration, a solution of EDTA of known concentration is slowly added to the solution containing the metal ion. A suitable indicator is typically used to signal the endpoint of the titration. The indicator changes color when all the metal ions have reacted with the EDTA and excess EDTA begins to bind with the indicator. The volume of EDTA solution used to reach the endpoint is then used to calculate the concentration of the metal ion in the original sample.

Complexometric titrations are versatile and can be used to determine the concentration of a wide range of metal ions, including calcium, magnesium, zinc, and copper. They find applications in various fields, such as water quality analysis, pharmaceutical quality control, and food analysis. The accuracy of the method depends on factors like the stability of the metal-EDTA complex and the choice of indicator.