2,4,4'-Trichloro-1,1'-biphenyl-C is a well-characterised trichlorinated biphenyl congener (PCB 28) widely used as an analytical reference standard in environmental monitoring, food safety testing, and toxicological research.
- Chemical Name
- 2,4,4'-Trichloro-1,1'-biphenyl (PCB 28)
- SKU
- T1539331
- Congener Number
- PCB 28 (Ballschmiter & Zell numbering)
- Molecular Formula
- C12H7Cl3
- Molecular Weight
- 257.54 g/mol
- Primary Use
- Analytical reference standard for PCB congener quantification
- Storage Condition
- Store in a cool, dry, well-ventilated area away from light; follow local regulations for halogenated organics
What Is 2,4,4'-Trichloro-1,1'-biphenyl-C (PCB 28)?
2,4,4'-Trichloro-1,1'-biphenyl, commonly designated PCB 28 under the Ballschmiter and Zell congener-numbering system, belongs to the polychlorinated biphenyl (PCB) family — a group of 209 synthetic chlorinated aromatic compounds once widely used as dielectric fluids, plasticisers, and flame retardants. PCB 28 carries three chlorine substituents positioned at the 2, 4, and 4' carbons of the biphenyl scaffold, giving it a molecular formula of C12H7Cl3 and a molecular weight of approximately 257.54 g/mol.
Although the commercial production of PCBs was banned in many jurisdictions following recognition of their environmental persistence and toxicity, PCB 28 remains an important analytical target in regulatory monitoring programmes (e.g., EU Regulation on dioxins and PCBs in food and feed, US EPA Method 8082A) and in fundamental toxicological and ecotoxicological research. Aladdin Scientific offers PCB 28 (SKU: T1539331) as a certified-grade reference standard to support accurate congener-specific analysis.
Key Physical and Chemical Properties
PCB 28 is a solid or viscous liquid at room temperature (the exact physical state may vary with purity and formulation). It is practically insoluble in water but readily dissolves in common organic solvents such as hexane, acetone, dichloromethane, and toluene — properties that underpin its environmental behaviour and dictate the solvent systems used in analytical extraction and standard preparation.
Key characteristics relevant to laboratory use include:
- Molecular Formula: C12H7Cl3
- Molecular Weight: ~257.54 g/mol
- Log Kow: approximately 5.7 (high lipophilicity; bioaccumulative) — verify against primary source
- Vapour Pressure: low; inhalation risk increases with heating
- Stability: photochemically and thermally stable; resistant to biodegradation
Because PCB 28 is a regulated persistent organic pollutant (POP) under the Stockholm Convention, all handling must comply with applicable national and institutional regulations.
Applications in Research and Analytical Testing
As a purified reference standard, 2,4,4'-Trichloro-1,1'-biphenyl-C (T1539331) serves multiple roles in scientific and regulatory laboratories:
- Environmental Monitoring: Quantification of PCB 28 in soil, sediment, water, and air samples as part of site-contamination assessments and compliance testing with regulatory thresholds.
- Food and Feed Safety: Indicator PCB analysis in fatty foods (fish, meat, dairy) per EU and Codex Alimentarius guidelines; PCB 28 is one of the six EU indicator PCBs (PCBs 28, 52, 101, 138, 153, 180).
- Toxicological and Mechanistic Research: Studying endocrine disruption, thyroid hormone interference, immunotoxicity, and developmental neurotoxicity attributable to lower-chlorinated PCB congeners.
- Method Development and Validation: Preparing calibration curves, spike-recovery experiments, and proficiency-testing samples for GC-ECD and GC-MS/MS analytical methods.
- Ecotoxicology: Investigating bioaccumulation, biomagnification, and metabolic transformation pathways in aquatic and terrestrial organisms.
Safe Handling, Storage, and Disposal
Hazard Classification: PCB 28 is classified as a persistent organic pollutant and a suspected human carcinogen (IARC Group 2A for the PCB class as a whole). It is toxic to aquatic life with long-lasting effects. Always consult the Safety Data Sheet (SDS) before use.
Personal Protective Equipment (PPE): Wear nitrile or neoprene gloves, lab coat, and safety goggles as a minimum. Work in a chemical fume hood when preparing solutions or performing operations that may generate vapour or aerosol.
Storage: Store in a tightly sealed container in a cool (below 25 °C), dry, well-ventilated area away from direct sunlight and ignition sources. Segregate from oxidisers and food/feed products. Follow institutional and local regulatory requirements for storage of halogenated organic compounds.
Disposal: PCBs are subject to strict waste-disposal regulations in most jurisdictions. Do not dispose of via drain, sewer, or general waste. Arrange for disposal through a licensed hazardous-waste contractor in accordance with applicable regulations (e.g., TSCA in the USA, Waste Framework Directive in the EU).
Ordering and Specification Information
Aladdin Scientific supplies 2,4,4'-Trichloro-1,1'-biphenyl-C under SKU T1539331. For pricing, available pack sizes, certificates of analysis (CoA), and safety data sheets, please contact your regional Aladdin Scientific representative or visit the product page on our website.
When ordering, please confirm:
- Required quantity and pack size
- Purity grade and any specific certification requirements (e.g., ISO 17034-accredited reference material)
- Required documentation (CoA, SDS, REACH/RoHS compliance letters if applicable)
- Shipping conditions — PCB standards may be subject to import/export restrictions in certain countries; buyers are responsible for compliance with applicable import regulations
For bulk enquiries, custom concentrations, or method development support, please contact our technical sales team directly.
Frequently asked questions
What is PCB 28 and why is it used as a reference standard?
PCB 28 (2,4,4'-Trichloro-1,1'-biphenyl) is one of 209 polychlorinated biphenyl congeners and is designated as one of the six EU indicator PCBs used to estimate total PCB contamination in food and environmental samples. As a purified reference standard (SKU: T1539331), it enables laboratories to prepare calibration solutions, validate analytical methods (e.g., GC-ECD, GC-MS), and achieve traceable quantitative results in compliance with regulatory requirements.
Which solvents are recommended for dissolving and diluting PCB 28 reference standards?
PCB 28 is highly soluble in non-polar and moderately polar organic solvents. Hexane, isooctane, and acetone are most commonly used in environmental analytical methods (e.g., EPA 8082A), while dichloromethane and toluene are also suitable. Avoid aqueous solutions, as PCB 28 has extremely low water solubility. Always prepare and handle solutions in a chemical fume hood.
Is a certificate of analysis (CoA) available for T1539331?
Yes. Aladdin Scientific provides a certificate of analysis for T1539331 documenting purity, lot number, and analytical results. Please request the CoA at the time of ordering or download it from the product page on the Aladdin Scientific website using the lot number printed on your product label.
What regulatory frameworks govern the use and disposal of PCB 28 in the laboratory?
PCB 28 falls under multiple regulatory regimes. In the USA, PCBs are regulated under the Toxic Substances Control Act (TSCA). In the EU, Regulation (EC) No 850/2004 on persistent organic pollutants applies. Globally, PCBs are listed under Annex A of the Stockholm Convention. Waste PCB materials must be disposed of through licensed hazardous-waste contractors; drain disposal is prohibited. Always check current national and institutional requirements before use.
How should PCB 28 standard solutions be stored to ensure stability?
Stock solutions of PCB 28 in organic solvents (e.g., hexane or isooctane) should be stored in amber glass vials with PTFE-lined caps at or below 4 °C, protected from light. Avoid plastic containers, as PCBs can adsorb onto certain polymers. Under these conditions, solutions are generally stable for at least 12 months, but verify stability as stated on the CoA and check for solvent evaporation before each use.
References
- Ballschmiter K, Zell M. Analysis of polychlorinated biphenyls (PCB) by glass capillary gas chromatography. Fresenius Z Anal Chem. 1980;302:20–31. [PCB congener numbering system]
- US EPA Method 8082A: Polychlorinated Biphenyls (PCBs) by Gas Chromatography. United States Environmental Protection Agency, 2007.
- European Commission Regulation (EC) No 1259/2011 amending Regulation (EC) No 1881/2006 as regards maximum levels for dioxins, dioxin-like PCBs and non dioxin-like PCBs in foodstuffs.
- IARC Working Group. Polychlorinated Biphenyls and Polybrominated Biphenyls. IARC Monographs Vol. 107. International Agency for Research on Cancer, 2016.
- Stockholm Convention on Persistent Organic Pollutants, Annex A: Elimination. United Nations Environment Programme.
Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.