Description

Eriochrome Black T is a high-purity metallochromic indicator dye, widely recognized for its critical role in complexometric titrations. Its primary value lies in providing a sharp, clear color change endpoint for the precise determination of metal ions, particularly calcium and magnesium in water hardness analysis. This product is essential for analytical laboratories, water treatment facilities, and quality control departments in industries ranging from pharmaceuticals to environmental monitoring. We supply Eriochrome Black T CAS NO 1787-61-7 in consistent, high-quality grades to ensure reliable and reproducible analytical results.

Application

• Complexometric Titration: Primary use as a visual indicator for the titration of calcium, magnesium, and other divalent cations using EDTA.
• Water Hardness Analysis: Standard method for determining total hardness (Ca²⁺ and Mg²⁺) in potable, industrial, and wastewater.
• Analytical Chemistry Reagent: Used in the preparation of standardized solutions for educational, research, and industrial analytical procedures.
• Dyeing and Staining: Employed in histological staining and as a colorimetric agent in certain biochemical assays.
• Metallurgy and Mining: Assists in the analytical determination of metal ion concentrations in ores, process streams, and effluents.
• Pharmaceutical QC: Used in testing where metal ion content or water quality is a critical parameter for raw materials or finished products.

Basic Information

Product Name	Eriochrome Black T
CAS No.	1787-61-7
Molecular Formula	C20H12N3NaO7S
Molecular Weight	461.38 g/mol
Synonyms	Solochrome Black T; Mordant Black 11; Chrome Black ET; CI 14645; 1-(1-Hydroxy-2-naphthylazo)-6-nitro-2-naphthol-4-sulfonic acid sodium salt; 3-Hydroxy-4-[(1-hydroxy-2-naphthyl)azo]-7-nitro-1-naphthalenesulfonic acid sodium salt; EBT
EINECS	217-250-2

Quality Control

Our Eriochrome Black T is manufactured and tested under a stringent quality management system to guarantee batch-to-batch consistency and performance. Each lot is analyzed to meet precise specifications for identity, purity, and suitability for use as a complexometric indicator. A comprehensive Certificate of Analysis (COA) detailing assay, impurity profile, and performance test results is provided with every shipment to support your quality assurance protocols.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). Keep away from incompatible materials. The product is light-sensitive (store away from light).

Specification

Item	Specification
Appearance	Dark brownish-black powder
Identification (IR)	Conforms to standard
Assay (HPLC)	≥ 85.0%
Loss on Drying	≤ 5.0%
Suitability Test	Passes (as indicator for EDTA titration)
pH (1% solution)	5.0 - 7.0

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.