Description

Alizarin-5-Sulfonic Acid is a water-soluble, sulfonated derivative of the classic anthraquinone dye alizarin. This compound is valued for its strong chelating properties and its ability to form vivid, stable complexes with various metal ions. It serves as a critical intermediate and analytical reagent in several high-tech industries. Key users include manufacturers and research laboratories in the chemical, analytical, and specialty materials sectors.

Application

• Analytical Chemistry Reagent: Primarily used as a sensitive colorimetric reagent for the spectrophotometric determination of aluminum, fluoride, and other metal ions.
• Complexometric Indicator: Employed in titrations, particularly for aluminum and rare earth elements, due to its distinct color change upon chelation.
• Dye Intermediate: Acts as a key precursor in the synthesis of more complex acid dyes and mordant dyes for textiles and histology.
• Biological Staining: Used in specific histological staining protocols to highlight particular tissue structures.
• Chemical Sensor Development: Incorporated into sensor materials and indicator papers for the detection of specific cations in environmental and industrial samples.
• Catalysis Research: Serves as a ligand in the preparation of metal-organic complexes for catalytic applications.

Basic Information

Item	Detail
Product Name	Alizarin-5-Sulfonic Acid
CAS No.	6373-42-8
Molecular Formula	C14H8O7S
Molecular Weight	320.27 g/mol
Synonyms	Alizarin Red S; Alizarin Carmine; Alizarinsulfonic Acid; 3,4-Dihydroxy-9,10-dioxo-9,10-dihydroanthracene-2-sulfonic Acid; 1,2-Dihydroxyanthraquinone-3-sulfonic Acid; Mordant Red 3; C.I. 58005; Sodium Alizarinsulfonate (common salt form)
EINECS	228-925-9

Quality Control

Our Alizarin-5-Sulfonic Acid is manufactured under a strict quality management system. Each batch undergoes comprehensive analytical testing, including identification (IR), purity assay (HPLC/Titration), and impurity profiling to ensure it meets precise specifications. A Certificate of Analysis (COA) documenting these results is provided with every shipment and is available upon request.

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 strong acids and incompatible materials. The product is light-sensitive; prolonged exposure to light should be avoided to maintain stability.

Specification

Item	Specification
Appearance	Orange-red to brownish-red powder
Identification (IR)	Conforms to structure
Assay (Titration)	≥ 95.0%
Loss on Drying	≤ 2.0%
Residue on Ignition (Sulfated Ash)	≤ 0.5%
Heavy Metals (as Pb)	≤ 20 ppm
Water Solubility	Clear, orange-red solution

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