Acid black 26 , CAS No.6262-07-3

CAS: 6262-07-3 Cat. No.: A1450795 Formula: C₃₂H₂₁N₅Na₂O₇S₂ Peso molecolare: 697.65 Numero EC: 228-412-8

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

Panoramica

Acid black 26 is a black agent whose coloring effect can be removed by adsorbents such as zeolites.

Specifications

Condizioni di conservazione di stoccaggio

Store at -20°C

Spedito in

Ice chest + Ice pads

Questo prodotto richiede spedizione a catena fredda. I servizi di terra e altri servizi economici non sono disponibili.

Nomi e identificatori

Peso molecolare

697.65

Application Protocols

• No vendor-validated protocols are provided for this item.

General starting points (literature/practice) for acid dye use; adjust to your application and verify for this specific dye lot:

• Stock solution preparation:
  • Weigh dye accurately; dissolve in deionized water to 1–10 g/L; warm gently and stir to aid dissolution. Filter (0.45 µm) to remove insolubles. Record λmax for the prepared stock.
• Adsorption experiment (batch):
  • Mix known mass of adsorbent with dye solution at set pH/ionic strength; sample over time; measure absorbance; fit to isotherm/kinetic models (e.g., Langmuir, Freundlich; pseudo-first/second order).
• Staining test (materials):
  • Immerse cleaned substrate in dye bath at target pH and temperature; agitate for a defined time; rinse and dry; quantify shade by reflectance colorimetry if needed.

Important:

• Parameters such as λmax, extinction coefficient, optimal pH, and solubility must be established empirically for this item (CAS 6262-07-3) using the CoA/SDS and small-scale pilots before critical work.

Biological Roles

• This product is supplied for research use only. No biological function or role is assigned to Acid Black 26 as a metabolite or signaling molecule.

General context (literature):

• Anionic azo dyes can bind noncovalently to protonated amino groups in proteins and polyamines via electrostatic interactions and π–π stacking; this underlies their use as acid dyes for proteinaceous materials. Such binding is nonspecific and driven by charge and hydrophobic interactions rather than defined biological targets.
• Some azo dyes can undergo reductive cleavage by azoreductases in microbial systems, yielding aromatic amines; this is primarily an environmental microbiology consideration rather than a physiological role.

Laboratory cautions:

• Avoid interpreting dye binding or color changes as evidence of specific biochemical interactions without appropriate controls (ionic strength, pH, competing ligands).
• When using as a tracer in biological matrices, confirm cytocompatibility and interference with assays (absorbance/fluorescence overlap) before use.

No claims are made regarding diagnostic, therapeutic, or in vivo applications. Consult the SDS and CoA for any additional restrictions and handle exclusively within research laboratory settings.

Buffer Applications

• Acid Black 26 is not a buffering agent and is not typically used to control pH. Therefore, conventional buffer recipes (e.g., phosphate, Tris, HEPES) do not apply.

Relevant considerations when using this dye in buffered systems (general):

• pH dependence: the absorbance spectrum and substrate uptake of acid dyes can vary with pH due to changes in ionization and azo tautomerism. Establish and report the working pH for reproducibility.
• Ionic strength: salts can influence dye–substrate interactions (salting-out/in effects). Maintain constant ionic strength across experiments.
• Compatibility: avoid buffers that strongly complex or reduce azo groups; phosphate, acetate, and citrate buffers are commonly compatible for aqueous staining baths at pH ~3–6 (verify for this item).

Practical tip:

• When preparing a dye solution in buffer, dissolve the weighed dye in a small volume of water first, then adjust with concentrated buffer to the final composition to avoid local high-ionic-strength zones that can precipitate impurities.

Green Alternatives

Context: Acid Black 26 is an anionic azo dye. “Greenness” considerations relate mainly to solvent choice, waste minimization, and avoidance of aromatic amine byproducts.

Options and trade-offs (general):

• Solvent system:
  • Greener choice: water or water–ethanol mixtures for dissolution and staining (low VOC, low toxicity).
  • Less preferred: high-boiling polar aprotics (DMF, NMP) due to worker exposure concerns; use only if necessary for solubility.
• Analytical use:
  • Replace dichromated or heavy-metal-containing mordants with salt-only or biomordant strategies where feasible.
• Alternative dyes:
  • Consider food-grade or biosourced colorants for demonstrations and noncritical teaching applications, recognizing differences in substantivity, photostability, and spectral properties.
• Process improvements:
  • Implement closed-loop baths and adsorbent regeneration (e.g., biochar, zeolites) in environmental studies to reduce dye discharge.

Small comparison (general):

• Acid Black–class azo dye vs. natural tannin-based dyes:
  • Performance: azo dye typically offers higher molar absorptivity and bath reproducibility.
  • Green profile: natural dyes may reduce hazard profile but can vary in composition and shade; batch-to-batch variability may limit quantitative work.

Guidance: Choose aqueous systems by default; validate that greener substitutes meet the spectroscopic and performance requirements of your protocol.

Pharmaceutical Uses

• No pharmacopeial status or excipient grade is provided for this item. It is supplied strictly for research use only.

General context (literature/industry):

• Certain dyes are used as colorants in topical or oral formulations when they meet compendial purity and toxicology requirements (e.g., FD&C dyes). Acid Black 26 is not indicated here as a compendial colorant; do not use for human or veterinary applications.
• Potential research-adjacent uses include: process visualization, equipment leak tracing, or in vitro formulation screening to track diffusion and adsorption on materials. Such uses remain nonclinical and require validation of compatibility and extractables/leachables.

Guidance for formulation research (nonclinical):

• Verify solubility and stability in the chosen excipient matrix and pH range.
• Filter solutions to remove particulates; document concentration by UV–Vis with an internal standard curve.
• Assess potential interference with analytical methods (spectral overlap with APIs or excipients).

Disclaimer: No medical, diagnostic, or therapeutic applications are supported. Refer to the CoA/SDS for purity profile and restrictions before any formulation-related study.

Physical Properties

Item-specific specifications:

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
• Melting point, boiling point, density, refractive index, UV–Vis maxima, pKa/logP: Not specified for this item; refer to CoA/Spec Sheet.

General/literature expectations for Acid Black–type azo dyes (for context only; verify for this exact CAS before method development):

• Physical form: typically a dark brown/black powder or granules; strongly colored in solution due to extended π-conjugation.
• Solubility: commonly water-soluble (as sulfonate salts); solubility can increase in warm water and in aqueous alcohols. Limited solubility is typical in nonpolar organic solvents.
• Spectroscopy: azo dyes exhibit intense visible absorption bands; λmax and extinction coefficients depend on substituents and ionization state. Acidic to neutral pH often preserves the anionic sulfonate form with robust color.
• Thermal behavior: dyes can char/decompose rather than show a sharp melting point; azo linkages may cleave under strong reducing conditions.

Practical notes (general):

• Prepare solutions gravimetrically and record exact concentration; filter (0.45 µm) to remove particulates before spectroscopic or staining use.
• Because dye purity and counterion content can influence color strength and bath behavior, calibrate against an internal standard curve when quantitative colorimetry is required.

Quality and Grades

• Grade/purity: Not specified for this item; refer to CoA/Spec Sheet.

How to interpret grade for dye reagents (general guidance):

• Analytical or spectrophotometric grade dyes are controlled for low inorganic salt content, defined dye content (color strength), and minimal insolubles—important for quantitative colorimetry or microscopy.
• “Technical” grades may contain extenders, inorganic salts, or byproducts from diazotization/coupling steps; suitable for general staining or textile simulations but less ideal for analytical use.
• Counterion content (e.g., sodium vs. mixed salts) and moisture can alter mass-based dosing; for precise work, standardize solutions by absorbance at known λmax rather than by weight.

What to check on the CoA for this item:

• Dye content/color strength method, insolubles/ash, moisture (LOD), UV–Vis identity (λmax and E values), and any listed impurities (e.g., aromatic amines).
• Stabilizers/additives: Not specified for this item; refer to CoA/Spec Sheet.

Practical QA tips:

• Record lot number and prepare a reference absorbance curve for your workflow.
• Filter or centrifuge stock solutions to remove particulates before use in imaging/assays.
• For cross-lab comparability, document solvent composition, pH, and pathlength when reporting absorbance-based concentrations.

Reaction and Applications

This product is a finished dye and is not typically used as a reagent or substrate in organic synthesis. Therefore, classical reaction-family guidance (e.g., cross-coupling, Grignard) does not apply.

Applicable use domains (general, laboratory):

• Colorant/staining studies: evaluation of adsorption, diffusion, and desorption on polymers, membranes, ion-exchange resins, and biomaterials under acidic conditions typical for acid dyes.
• Analytical/colorimetric method development: calibration of spectrophotometers in the visible range; preparation of reference curves for teaching labs or QC exercises (ensure the exact λmax and extinction coefficient are established for the specific lot).
• Environmental and separation science: model anionic dye in adsorption/photodegradation experiments (e.g., photocatalysis, advanced oxidation). Document pH, ionic strength, and light intensity, as these factors strongly influence kinetics and pathways.

Practical tips (general):

• Prepare fresh aqueous stocks; filter (0.22–0.45 µm) to remove particulates.
• Control pH and ionic strength to ensure reproducible uptake onto substrates.
• Protect solutions from prolonged intense light if photolysis or fading would bias measurements.

Note: When using the dye as a tracer or probe, confirm spectral characteristics and stability for your exact matrix and pH; do not assume transferability from other Acid Black dyes.

Reaction Conditions

Conventional synthetic reaction conditions are not generally applicable to this product as a dye. However, for experiments where Acid Black–type dyes are used as probe molecules (general literature guidance):

• Aqueous adsorption tests:
  • Solvent: deionized water or buffered water (pH 3–6 for acid dyes).
  • Temperature: 20–30°C typical; report and maintain constant temperature for kinetic comparisons.
  • Concentration: prepare standard solutions across a relevant range (e.g., 5–200 mg/L), verifying linearity of absorbance.
  • Contact time: minutes to hours depending on substrate; monitor until apparent equilibrium.
• Photocatalytic degradation:
  • Light source: specify wavelength or irradiance; include actinometry or a calibrated radiometer.
  • Catalyst loading: as per literature for TiO2, ZnO, etc.; stir vigorously to avoid mass-transfer limitations.
  • Analytical: follow λmax for the dye; confirm mineralization by TOC or LC–MS when mechanism matters.
• Staining baths (materials testing):
  • pH: mildly acidic; adjust with acetic/citric acid as needed.
  • Additives: electrolytes may be used to modulate uptake; validate for your substrate.

All values above are general literature practices for acid dyes and must be optimized for this specific item and use case.

Safety and Handling

Product-specific hazard information:

• Signal word: Not specified for this item; refer to SDS.
• H-statements: Not specified for this item; refer to SDS.
• GHS classification and pictograms: Not specified for this item; refer to SDS.

General safety guidance for anionic azo dyes (literature/practice; not a substitute for SDS):

• Potential hazards: dust may cause mechanical irritation to eyes and respiratory tract; prolonged skin contact can cause staining and irritation. Some azo dyes can release aromatic amines upon metabolic or chemical reduction—avoid ingestion and inhalation of dust/fumes.
• PPE: safety glasses or goggles, lab coat, disposable nitrile gloves. Handle powders in a fume hood or at least a well-ventilated area; minimize dust generation.
• Incompatibilities: strong oxidizers (may degrade chromophore), strong reducing agents (may cleave –N=N– bonds), strong acids/bases at elevated temperature (may hydrolyze functional groups).
• First aid (overview):
  • Inhalation: move to fresh air; seek medical attention if symptoms persist.
  • Skin contact: wash with soap/water; remove contaminated clothing.
  • Eye contact: rinse cautiously with water for several minutes; remove contact lenses if present and easy to do; seek medical advice if irritation persists.
  • Ingestion: rinse mouth; do not induce vomiting; seek medical advice.
• Spill response: avoid dust; sweep up with dampened absorbent; dispose of according to institutional and local regulations.
• Defer to the official SDS for authoritative, product-specific safety measures.

Solvent Selection

Item-specific solvent data: Not specified for this item; refer to CoA/Spec Sheet.

General guidance for Acid Black–class dyes (literature):

• Polarity/class: strongly polar, anionic dye (typically as sulfonate salt). Best handled in water or aqueous buffers; limited compatibility with nonpolar media.
• Miscibility profile:
  • Water: typically readily soluble; warming and mild stirring expedite dissolution.
  • Alcohol–water mixtures: often useful for faster wetting and reduced foaming.
  • Pure organic solvents (e.g., MeCN, DMF, DMSO): solubility varies by structure; small aliquots of DMSO can be used to prepare concentrated stocks, then diluted into water.
• pH considerations: color strength and substantivity often optimized in mildly acidic media where cationic sites on substrates (e.g., polyamides, proteins) are protonated.

Selection tips:

• For spectroscopy: use deionized water or defined buffers; filter before measurement.
• For staining baths: aqueous solutions with controlled pH/ionic strength to tune uptake; consider addition of salt (e.g., Na2SO4) only if compatible with your protocol.
• For polymer/fiber studies: water or water–alcohol blends to simulate industrial dye baths.

Comparison (general):

• Acid Black dyes vs. basic/cationic dyes: choose acid dyes for substrates with protonated amine sites; choose basic dyes for anionic substrates (e.g., acrylics).

Storage and Reconstitution

Product-specific:

• Storage conditions: Store at -20°C (as provided in Product Data). Keep container tightly closed, desiccated if possible, and protected from light to maintain color integrity.
• Shipping: Shipped in an ice chest with ice pads (as provided in Product Data) to limit thermal excursions.

General handling guidance for dye solids/solutions:

• Upon receipt: allow the sealed container to equilibrate to room temperature before opening to minimize moisture condensation. Record lot number and date opened.
• Solid stability: dyes are typically stable in dry, dark, cool storage. Avoid repeated warming/cooling cycles.
• Reconstitution: Solvent and concentration are not specified for this item; refer to CoA/Spec Sheet. As a general practice for acid dyes, start with deionized water to make a concentrated stock (e.g., 1–10 g/L), warming gently if needed, then filter (0.22–0.45 µm).
• Aliquoting: prepare working aliquots to avoid repeated freeze–thaw of aqueous stocks. Store aqueous stocks refrigerated (short term) or frozen (longer term) and protect from light. Verify stability by periodic absorbance checks at λmax.
• Disposal: collect dye-containing wastes separately; treat according to institutional and local regulations, especially for experiments that generate aromatic amines via reduction/oxidation.

Note: For any item-specific solubility, pH limits, or stabilizers, consult the CoA/Spec Sheet and SDS.

Structure and Identity

• Item name: Acid black 26 (Color Index name)
• CAS: 6262-07-3 (product-specific)
• Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
• SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• InChIKey: Not specified for this item; refer to CoA/Spec Sheet.

General chemistry (literature):

• Acid Black dyes are typically anionic azo dyes containing one or more –N=N– (azo) linkages conjugated to polyaromatic systems and bearing sulfonate (–SO3−) substituents for water solubility. Acid Black 26 is reported in dye literature as a polyazo dye with multiple aromatic rings and sulfonate counterions (often sodium) to confer high aqueous affinity for cationic substrates (e.g., protonated amines in proteinaceous materials or polyamide fibers).
• 2D structural features (descriptive, literature): extended π-conjugated aromatic scaffold(s) bridged by azo groups; electron-donating/withdrawing balance across rings; one or more sulfonate groups positioned to enhance solubility and substantivity under acidic conditions. No stereogenic centers are expected in typical members of this class.

Notes:

• Exact structural identifiers for this catalog item are not provided above and should be confirmed against the product CoA/Spec Sheet or SDS before use in regulated or quantitative applications.

Synthetic Utility

• As a finished chromophore, Acid Black 26 is not commonly employed as a synthetic intermediate. Its primary utility lies in its optical properties rather than chemical reactivity.

General chemical features (literature) that could be leveraged in method development studies (not typical synthesis):

• Azo linkage (–N=N–): susceptible to reductive cleavage under strong reducing conditions, producing anilines/naphthylamines—useful in mechanistic or degradation studies but not generally targeted in routine synthesis due to selectivity/toxicity concerns.
• Sulfonate groups: confer water solubility and anionic character; enable ion-pair and ion-exchange interactions in separations research.
• Extended conjugation: strong visible absorbance facilitates real-time monitoring of adsorption, diffusion, and reaction progress in heterogeneous systems.

Applications in materials/analytical chemistry:

• Tracer for transport studies in hydrogels, membranes, and porous catalysts.
• Probe molecule for validating advanced oxidation processes and photocatalysts (kinetic benchmarking).

Note: If chemical transformation of the dye is intended, thoroughly evaluate byproduct profiles and ensure appropriate containment and waste handling, as reduction/oxidation can form aromatic amines or sulfonated fragments of regulatory concern.

Target Specificity

• Not an antibody or affinity reagent; no antigen, clone, or species specificity applies.

General note:

• Any apparent “specificity” in materials or biological staining arises from physicochemical interactions (charge, hydrophobicity, porosity) rather than selective binding to a defined molecular epitope. Validate selectivity empirically with appropriate controls and counterstains when needed.