Description

7-Hydroxy-8-[(4-Sulfo-1-Naphthalenyl)Azo]-1-Naphthalenesulfonic Acid Disodium Salt is a high-purity, water-soluble azo dye intermediate and analytical reagent. Its primary value lies in its strong chelating properties and vivid color formation, making it a critical component for precise colorimetric analysis and specialized dye synthesis. This compound is essential for manufacturers and laboratories in the chemical, analytical, and textile industries requiring consistent and reliable performance.

Application

• Complexometric Indicator: Widely used as a metallochromic indicator in the titration of metal ions, particularly calcium and magnesium, in analytical chemistry and water hardness testing.
• Dye Intermediate: Serves as a key precursor in the synthesis of specific acid dyes and reactive dyes for textiles, leather, and paper.
• Biological Staining: Employed in histological and cytological staining procedures for microscopic analysis in life science research.
• Photometric Reagent: Used in spectrophotometric methods for the quantitative determination of trace metals in environmental, pharmaceutical, and industrial samples.
• Chelating Agent: Functions as a selective complexing agent in separation processes and metal ion buffering systems.
• Laboratory Reagent: Supplied as a high-purity standard for quality control and calibration in analytical laboratories.

Basic Information

Item	Detail
Product Name	7-Hydroxy-8-[(4-Sulfo-1-Naphthalenyl)Azo]-1-Naphthalenesulfonic Acid Disodium Salt
CAS No.	5858-93-5
Molecular Formula	C20H12N2Na2O8S2
Molecular Weight	518.42 g/mol
Synonyms	Acid Chrome Blue K; Chrome Azurol S; Mordant Blue 29; C.I. 43825; 3-[2-[4-(3-Carboxy-5-methyl-4-oxo-2,5-cyclohexadien-1-ylidene)-2,5-cyclohexadien-1-ylidene]hydrazinyl]benzoic Acid Disodium Salt; NSC 403697; 1-Naphthalenesulfonic acid, 7-hydroxy-8-[(4-sulfo-1-naphthalenyl)azo]-, disodium salt
EINECS	227-490-3

Quality Control

Our 7-Hydroxy-8-[(4-Sulfo-1-Naphthalenyl)Azo]-1-Naphthalenesulfonic Acid Disodium Salt is manufactured under a strict quality management system. Every batch undergoes comprehensive analytical testing, including HPLC for purity and identity confirmation, to ensure it meets precise specifications for use as an analytical reagent. Certificates of Analysis (COA) documenting all critical parameters are available upon request to support your quality assurance protocols.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at a controlled room temperature (15-25°C). Due to its hygroscopic (moisture-sensitive) nature, the container must be kept tightly sealed after each use to prevent absorption of atmospheric moisture, which can affect purity and performance.

Specification

Item	Specification
Appearance	Dark brown to reddish-brown powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 95.0%
Loss on Drying	≤ 5.0%
Residue on Ignition (Sulfated Ash)	20.0% - 25.0%
Heavy Metals (as Pb)	≤ 20 ppm
Water Solubility	Clear, complete solution

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