Eriochrome black metallochromic indicators

Erbium, tris(2,2,6,6-tetrametbyl-3,5-hep tanedione) structure, 1, 65, 66 Erbium complexes acetylacetone, 2, 374 Erhium(ill) complexes glycolic acid, 2, 472 Eriochalcite, 6, 855 Eriochrome black T metallochromic indicators, 1, 555 Eriochrome blue black R metallochromic indicators, I, 556 Eriochrome cyanine R metallochromic indicator, 1, 556 Erythrocruorin, 6, 689 dioxygen transport, 6,683 stability... 

The indicator used in the test, mordant black 11 triturate R, is a dry dilution of Eriochrome Black (Figure 6.7.3), which is one of the most widely used metallochromic indicators. The acid form of the indicator is red, changes to blue at about pH 6, and to orange at pH 12. Only the blue is used as a metallochrome indicator, and it changes to red in the presence of metals. 

A large number of metallochromic indicators have been proposed for the detection of the equivalence point for the titration of the rare earths with EDTA and other polydentate ligands. These include Alizarin Red, Arsenazo I, Xylenol Orange, Eriochrome Black T, and Murexide to name only a few. The structure, conditions under which these indicators can be used, possible interferences, and references to the original papers are summarized by Aladjem (1970), p. 287. 

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See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

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