Description

o-Cresolphthalein Complexone Tetrasodium Salt is a high-purity, water-soluble metallochromic indicator and chelating agent. Its primary value lies in its exceptional selectivity for calcium ions, forming a distinct color change that enables precise quantitative analysis. This compound is essential for laboratories and manufacturers in the clinical diagnostics, water treatment, and pharmaceutical industries requiring accurate calcium determination.

Application

• Clinical Diagnostics: Key reagent in colorimetric assays for the quantitative determination of calcium in serum, plasma, and urine, used in automated clinical chemistry analyzers.
• Water Quality Analysis: Employed in complexometric titrations and test kits to measure water hardness by specifically chelating calcium ions.
• Pharmaceutical Manufacturing: Used in quality control processes to assay calcium content in raw materials, excipients, and finished drug products.
• Food & Beverage Testing: Applied in the analysis of calcium fortification levels and natural mineral content in dairy products, juices, and nutritional supplements.
• Biochemical Research: Serves as a selective calcium ion indicator in buffer solutions and experimental protocols for studying calcium-dependent biological processes.
• Industrial Process Control: Monitors calcium levels in boiler feed water, cooling systems, and various chemical process streams to prevent scaling.

Basic Information

Product Name	o-Cresolphthalein Complexone Tetrasodium Salt
CAS No.	62698-54-8
Molecular Formula	C32H24N2Na4O12
Molecular Weight	710.50 g/mol
Synonyms	o-Cresolphthalein Complexone, Tetrasodium Salt; CPC Tetrasodium Salt; 3',3''-Bis[N,N-bis(carboxymethyl)aminomethyl]-o-cresolphthalein Tetrasodium Salt; Phthalein Purple Tetrasodium Salt; o-Cresolphthalein-3',3''-bis(methyliminodiacetic acid) Tetrasodium Salt; Calcium Colorimetric Indicator; o-CPC; CAS 62698-54-8
EINECS	Contact for details

Quality Control

Our o-Cresolphthalein Complexone Tetrasodium Salt is manufactured under a strict quality management system. Each batch undergoes rigorous analytical testing to ensure it meets high-purity standards suitable for sensitive analytical applications, including clinical diagnostics. A comprehensive Certificate of Analysis (COA) detailing purity, identity, and performance is provided with every shipment to guarantee traceability and batch-to-batch consistency.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at a controlled room temperature (15-25°C). This product is hygroscopic (moisture-sensitive); ensure the original container is securely sealed after each use to prevent absorption of atmospheric moisture, which can affect performance and stability.

Specification

Item	Specification
Appearance	White to off-white powder
Identification (IR)	Conforms to reference spectrum
Assay (HPLC)	≥ 95.0%
Loss on Drying	≤ 5.0 %
Absorbance Ratio (578 nm / 430 nm)	≥ 2.5 (in Calcium-containing buffer)
Heavy Metals (as Pb)	≤ 20 ppm
Calcium Binding Capacity	Conforms
Solubility (in Water)	Clear, colorless to faint pink solution

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