Eriochrome Blue Black R.

Structural formula
General
Surname	Eriochrome Blue Black R.
other names	Sodium 3-hydroxy-4 - [(2-hydroxy-1-naphthyl) diazenyl] -1-naphthalenesulfonate ( IUPAC ) CI Mordant Black 17th CI 15705 Calcon ( trade name ) Palatine chrome black 6 BN
Molecular formula	C 20 H 13 N 2 NaO 5 S
Brief description	black solid
External identifiers / databases
CAS number 2538-85-4 EC number 219-810-2 ECHA InfoCard 100.018.010 PubChem 135465074 ChemSpider 21159665 Wikidata Q1354782
properties
Molar mass	416.39 g mol −1
Physical state	firmly
solubility	little in water (20 g l −1 at 20 ° C)
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 315-319-335 P: 280-302 + 352-304 + 340-312-332 + 313-337 + 313
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Eriochrome Blue Black R , and calcon , is a water-soluble azo dye , as the complexometry - indicator for copper , aluminum , iron and zirconium is used. It is structurally similar to azorubine .

Properties and use

Calcon is a dark brown to black-violet colored powder that is soluble in water with a blue-violet color. A reduction in the pH value by adding acid causes the color to lighten.

The dye is structurally similar to the calcon carboxylic acid and forms very stable complexes with Al (III) ions . It can therefore be used for the very sensitive voltammetric determination of aluminum, for example in drinking water ; the sensitivity is around 5 μg l ⁻¹ solution.

Individual evidence

1. ↑ ^{a b c d} data sheet Eriochrome blue black R at Acros, accessed on May 15, 2017.
2. ↑ Chemical Dictionary : Eriochromblauschwarz R , accessed on November 24, 2019.
3. ↑ Metrohm ion analysis: Voltammetric aluminum determination , accessed on November 24, 2019.