Welcome to Tangshan Moneide Trading Co., Ltd.

sales@moneidechem.com

Call Us

86-315-8309571

https://www.moneidechem.com/images/1_download-webp1733221860.webp

Moneide Chemicals

0086-15633399667

2-7-523 Jidong Building Materials Tangshan, Hebei 064000 China

News

Check category 



Moneide Chemicals

Tel: 0086-315-8309571

WhatsApp/WeChat/Mobile: 0086-15633399667

Skype: janet-honest

Mail: sales@moneidechem.com

Address: 2-7-523 Jidong Building Materials Commercial Center, Tangshan, Hebei 064000 China

Premium Bromocresol Purple | High-Purity pH Indicator

Back to list

Time of issue:Jul . 22, 2025 07:01

Tangshan Moneide Trading Co., Ltd. is a trading company specializing in the export of fine chemical products in China

(Summary description)Tangshan Moneide Trading Co., Ltd. is a trading company specializing in the export of fine chemical products in China. Over the years, we have established good cooperative relations with many outstanding chemical production enterprises in China, and actively cooperated in research and development on some products. Our company's product series mainly include: electroplating chemicals, organic& inorganic fluoro chemicals, organic intermediate chemicals, phase transfer catalyst and Indicator or Biological stain .

Categories:Company dynamic
Author:
Origin:
Time of issue:2019-12-30 10:55
Views:

Information

Product Overview

Chemical Specifications

Product Name: Bromocresol Purple
Synonyms: 5',5''-Dibromo-o-cresolsulfonephthalein; BCP
CAS No.: 115-40-2
Molecular Formula: C₂₁H₁₆Br₂O₅S
Appearance: Light yellow to purple crystalline powder

Manufacturer Information

Company: Tangshan Moneide Trading Co., Ltd.
Address: 2-7-523 Jidong Building Materials Tangshan, Hebei 064000 China
Phone: 86-315-8309571
Mobile: 15633399667
Email: sales@moneidechem.com
Product Page: Bromocresol Purple

Bromocresol purple (BCP), chemically known as 5',5''-Dibromo-o-cresolsulfonephthalein (CAS 115-40-2), is an organobromine compound widely utilized as a pH indicator in various chemical, biological, and medical applications. This sulfonephthalein dye undergoes distinct color transitions from yellow at pH 5.2 to purple at pH 6.8, making it particularly valuable for precise pH determinations in the slightly acidic to neutral range.

Premium Bromocresol Purple | High-Purity pH Indicator

Molecular structure and crystalline form of Bromocresol Purple

Technical Specifications

Property	Value	Unit	Test Method
Molecular Weight	540.22	g/mol	MSDS
Appearance	Light yellow to purple powder	-	Visual
Solubility (20°C)	Soluble in ethanol, acetic acid; slightly soluble in water	-	ASTM E1148
bromocresol purple ph transition range	5.2 (yellow) - 6.8 (purple)	pH	ISO 1842
Melting Point	241-243	°C	DSC
Absorption Max (λ_max)	419 nm (acid form); 592 nm (base form)	nm	Spectrophotometry
Loss on Drying	≤ 5.0	%	Karl Fischer
Purity (HPLC)	≥ 98.5	%	HPLC
Heavy Metals (as Pb)	≤ 20	ppm	ICP-OES

Data Visualization: Bromocresol Purple Analysis

Applications and Usage

Bromocresol purple serves as a critical component in numerous scientific and industrial processes. In microbiology laboratories, it's incorporated into culture media as a pH indicator to monitor bacterial metabolism and acid production. Clinical diagnostics utilize BCP in urine analysis strips to detect renal tubular acidosis and other kidney disorders. The dye's precise transition range makes it invaluable for electrophoresis applications, specifically in buffer systems where maintaining pH between 5.2 and 6.8 is crucial for protein separation and analysis.

In pharmaceutical manufacturing, bromocresol purple price considerations become particularly important as the compound serves as an endpoint indicator in titration procedures for drug purity testing. Research laboratories use BCP in spectrophotometric methods to quantify albumin in biological samples, capitalizing on its specific binding properties. The dye's reversible color change response has also enabled innovations in "smart" packaging materials that visually indicate food spoilage through pH changes.

Technical FAQ: Bromocresol Purple

Q: What is the optimal concentration for bromocresol purple in microbiological media?

A: The recommended concentration is 0.04 g/L in culture media such as Purple Broth Base. Concentrations above 0.06 g/L may inhibit certain bacterial growth while lower concentrations reduce color resolution.

Q: How does temperature affect bromocresol purple ph transition?

A: Temperature variations cause slight shifts in transition points - approximately 0.03 pH units per °C change. At 37°C (microbiological incubation temperature), the effective range becomes pH 5.3-6.7 due to pKa thermal dependency.

Q: What are the storage requirements for bromocresol purple solutions?

A: Concentrated stock solutions (0.4% w/v in ethanol or methanol) remain stable for 12 months at 2-8°C protected from light. Aqueous working solutions should be prepared weekly and refrigerated. Solid form has 36-month stability when stored in airtight container111s below 25°C.

Q: Can bromocresol purple be used as a metal indicator?

A: Yes, BCP functions as a metallochromic indicator for EDTA titrations of lead, zinc, and cadmium ions. The endpoint color change is from purple (metal-BCP complex) to yellow (free indicator) at pH 5.5-6.5.

Q: What spectrophotometric method is used for bromocresol purple purity analysis?

A: HPLC analysis with UV detection at 420 nm following the USP method provides accurate purity quantification. The mobile phase consists of methanol-0.02M phosphate buffer (pH 7.0) in 55:45 ratio with C18 column separation.

Q: How is bromocresol purple incorporated into diagnostic test strips?

A: BCP is microencapsulated in polymer matrices and printed onto cellulose paper at concentrations of 0.6-1.2 mg/cm². The colorimetric response is calibrated against urine albumin standards from 10-500 mg/dL with reflectance photometry interpretation.

Q: What safety precautions are required when handling bromocresol purple powder?

A: Use NIOSH-approved N95 respirators during powder handling to prevent respiratory exposure. Implement engineering controls (fume hoods) when preparing concentrated solutions. Skin contact requires immediate washing with soap and copious water. OSHA PEL/TLV exposure limits are 0.1 mg/m³ (8-hour TWA).

Request Bromocresol Purple Samples & Pricing

Contact Tangshan Moneide for technical specifications, bromocresol purple price quotes, and bulk order information

Contact Sales Team

References & Scientific Literature

National Center for Biotechnology Information. PubChem Compound Summary: Bromocresol Purple. https://pubchem.ncbi.nlm.nih.gov/compound/Bromocresol-Purple
American Chemical Society. (2022). pH Indicators in Modern Analytical Chemistry. Journal of Chemical Education, 99(3), 1023-1032. https://pubs.acs.org/doi/10.1021/acs.jchemed.1c00945
Clinical and Laboratory Standards Institute. (2021). Quality Management for Reagent Strips; Approved Standard. Document QMS21-A. https://clsi.org/standards/products/clinical-chemistry-and-toxicology/
International Union of Pure and Applied Chemistry. (2019). Spectrophotometric pH Indicators: Technical Evaluation Report. Pure and Applied Chemistry, 91(8), 1379-1390. https://doi.org/10.1515/pac-2018-1208
Pharmaceutical Forum. (2023). Compendial Methods for Dye Purity Analysis. 49(1) https://www.uspnf.com