Cu-PAN, a mixture of Cu-EDTA and pyridylazo-naphthol PAN, is a very popular metal indicator for chelatometry. Usually, 20-50% aqueous dioxane (or isopropyl alcohol) or 50-70% aqueous methanol (or ethanol) is used as a solvent (1 g Cu-PAN per 100 ml solvent). The solution should be heated during the chelating titration.
Technical info
Chelate titration (acidic condition): Al, C, Co, Fe(III), Ga, Hg, In, Ni, V, Zn, rare earth metal ions Chelate titration (alkaline condition): Ca, Cu, Mg, Mn(II)
References
Open References
1) H. Flaschka and H. Abdine, "EDTA Titrations Using Copper-PAN Complex as Indicator", Chem. Anal., 1956,45, 58
Handling and storage condition
Specification
Appearance:
Grayish red brown to yellowish brown powder
Solubility in Dioxane:
To pass test (clear, yellowish brown to deep yellowish brown)