Description

Methyl Red CAS NO 493-52-7 is a synthetic azo dye widely recognized as a crucial pH indicator in analytical chemistry. Its distinct and reversible color change in the acidic pH range makes it an indispensable tool for precise endpoint determination in titrations and for monitoring chemical reactions. This high-purity compound is essential for laboratories, quality control departments, and manufacturing processes in the pharmaceutical, chemical, and educational sectors, where accurate pH measurement is non-negotiable.

Application

• pH Indicator in Titrations: Primarily used in acid-base titrations, especially for determining the endpoint in the titration of weak bases with strong acids.
• Microbiological Media: A key component in Methyl Red-Voges Proskauer (MR-VP) broth for the Methyl Red test, used to identify enteric bacteria based on mixed acid fermentation.
• Laboratory Reagent: Serves as a standard pH indicator solution for general laboratory use, educational demonstrations, and calibration references.
• Chemical Synthesis: Employed as an intermediate in the synthesis of other dyes and complex organic compounds.
• Industrial Process Monitoring: Used in certain industrial processes to visually monitor pH changes in real-time within specific acidic ranges.
• Research & Development: Utilized in various R&D applications, including the development of sensor materials and colorimetric assays.

Basic Information

Product Name	Methyl Red
CAS No.	493-52-7
Molecular Formula	C15H15N3O2
Molecular Weight	269.30 g/mol
Synonyms	Acid Red 2; C.I. 13020; 2-[4-(Dimethylamino)phenylazo]benzoic Acid; p-Dimethylaminoazobenzene-2'-carboxylic Acid; MR; Methyl Red Indicator; Gold Label Methyl Red
EINECS	207-776-1

Quality Control

Our Methyl Red is manufactured under strict quality management systems to ensure batch-to-batch consistency and high purity suitable for analytical applications. Each lot undergoes comprehensive testing, including identification (IR), assay (HPLC), and checks for specific impurities. A Certificate of Analysis (COA) detailing all test results is provided with every shipment to guarantee compliance with your specifications and industry standards.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at a controlled room temperature (15-25°C). This product is light-sensitive and should be stored away from direct light. Keep container tightly sealed when not in use to minimize exposure to air.

Specification

Item	Specification
Appearance	Dark red crystalline powder
Identification (IR)	Conforms
Assay (HPLC)	≥ 98.0%
Loss on Drying	≤ 0.5%
pH Transition Range	4.4 (red) to 6.2 (yellow)
Solubility (Ethanol)	Clear, complete solution
Heavy Metals (as Pb)	≤ 20 ppm

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