In the intricate world of chemical analysis, certain reagents stand out for their versatility and indispensable nature. Eriochrome Black T (CAS 1787-61-7) is unequivocally one such compound. Widely recognized for its role as a complexometric indicator, this azo dye is crucial for the accurate quantification of numerous metal ions, making it a staple in analytical laboratories worldwide. As a prominent manufacturer and supplier of this vital chemical, NINGBO INNO PHARMCHEM CO.,LTD. is proud to provide a high-purity product that facilitates precise metal ion determination.

Eriochrome Black T, also known by its Colour Index name Mordant Black 11, owes its effectiveness to its ability to form distinctly colored complexes with various metal ions. Its primary application lies in complexometric titrations, most notably with ethylenediaminetetraacetic acid (EDTA). The indicator undergoes a color change from blue (in a solution with a pH of 10 or higher, when free) to wine-red when it forms a complex with metal ions such as calcium, magnesium, zinc, and cadmium. As EDTA is added during the titration, it chelates the metal ions more strongly than Eriochrome Black T does. At the equivalence point, the EDTA displaces the indicator, causing a sharp color change back to blue. This distinct transition is essential for accurate endpoint detection.

Beyond its well-known application in determining total water hardness (the sum of calcium and magnesium ions), Eriochrome Black T is instrumental in the analysis of a much broader spectrum of metals. These include, but are not limited to, barium, indium, manganese, lead, scandium, strontium, and zirconium. This wide applicability makes it a highly economical choice for laboratories that perform diverse metal analyses, reducing the need for multiple specialized indicators.

The synthesis of Eriochrome Black T involves the careful diazotization of a nitroaniline derivative followed by coupling with a naphthol compound. The resulting molecule is a sophisticated organic dye designed for specific chelating properties. Ensuring high purity, typically above 97%, is critical for its reliable performance as an indicator. NINGBO INNO PHARMCHEM CO.,LTD. is committed to rigorous quality control throughout the manufacturing process to deliver a product that meets these exacting standards. If you are looking to buy Eriochrome Black T (CAS 1787-61-7) and require a dependable supplier with competitive prices, we encourage you to contact us for a quote and sample.