Description

Chromotropic Acid Disodium Salt is a high-purity organic chemical compound widely used as a key analytical reagent. Its primary commercial value lies in its exceptional sensitivity and selectivity for the spectrophotometric determination of formaldehyde and other aldehydes. This product is essential for industries and laboratories requiring precise analytical methods for environmental monitoring, industrial hygiene, and quality control processes.

Application

• Formaldehyde Analysis: The primary application is as a chromogenic reagent in the standard spectrophotometric method (e.g., NIOSH 3500, EPA methods) for detecting and quantifying formaldehyde in air, water, and various products.
• Aldehyde Detection: Used for the specific colorimetric determination of other aliphatic aldehydes in chemical and biochemical research.
• Environmental Testing: Critical for monitoring formaldehyde emissions in indoor air quality assessments, workplace safety, and industrial stack testing.
• Textile & Resin Industry QC: Employed in quality control laboratories to measure residual formaldehyde in textiles, fabrics, urea-formaldehyde resins, and other treated materials.
• Clinical & Histology Reagent: Serves as a specialized staining agent and fixative component in certain histological techniques.
• Chemical Synthesis Intermediate: Acts as a building block or precursor in the synthesis of dyes, pigments, and more complex organic molecules.

Basic Information

Product Name	Chromotropic Acid Disodium Salt
CAS No.	129-96-4
Molecular Formula	C10H6Na2O8S2
Molecular Weight	364.24 g/mol
Synonyms	1,8-Dihydroxynaphthalene-3,6-disulfonic Acid Disodium Salt; 4,5-Dihydroxynaphthalene-2,7-disulfonic Acid Disodium Salt; Chromotropic Acid Sodium Salt; Disodium Chromotropate; Disodium 4,5-Dihydroxy-2,7-naphthalenedisulfonate; Naphthalenedisulfonic Acid, 4,5-dihydroxy-, Disodium Salt
EINECS	204-964-2

Quality Control

Our Chromotropic Acid Disodium Salt is manufactured under strict quality management systems. Each batch undergoes rigorous analytical testing to ensure it meets high-purity standards suitable for sensitive analytical applications. Key parameters including assay (purity), absorbance characteristics, and suitability for formaldehyde testing are verified. A comprehensive Certificate of Analysis (COA) detailing all test results is provided with every shipment.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). Keep away from heat, sparks, and open flame. Due to its light-sensitive nature, prolonged exposure to direct light should be avoided to maintain reagent performance.

Specification

Item	Specification
Appearance	Off-white to pale yellow crystalline powder
Identification (IR)	Conforms
Assay (HPLC)	≥ 98.0%
Water Content (KF)	≤ 2.0%
Absorbance Test (for Formaldehyde)	Passes performance test
Residue on Ignition	≤ 0.2%
Heavy Metals (as Pb)	≤ 20 ppm

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