Industrial Purity 4-Aminobenzene Sulfonic Acid Coa Specifications
- Critical Assay Parameters: High-purity grades typically exceed 99.0% assay content with strict limits on free aniline.
- Physical Stability: Decomposes without melting at approximately 288°C (550°F), requiring specific storage conditions away from acids.
- Commercial Availability: Bulk procurement ensures consistent supply for dye intermediate applications and chemical synthesis.
In the realm of fine chemical manufacturing, the Certificate of Analysis (COA) serves as the definitive document verifying the quality and safety of a chemical raw material. For procuring entities involved in the production of azo dyes and organic intermediates, understanding the technical specifications of Sulfanilic Acid is paramount. This compound, chemically known as 4-aminobenzenesulfonic acid, demands rigorous quality control to ensure downstream reaction yields are not compromised by impurities. As a premier global manufacturer, NINGBO INNO PHARMCHEM CO.,LTD. adheres to strict industrial standards to deliver consistent industrial purity across all bulk shipments.
Understanding Industrial Purity Standards
The quality of any chemical intermediate begins with its manufacturing process. The primary synthesis route for this compound involves the sulfonation of aniline with concentrated sulfuric acid, followed by a baking process to form the zwitterionic structure. The efficiency of this reaction directly impacts the bulk price and the final assay value. Industrial grade material must minimize residual starting materials, particularly free aniline, which can pose significant safety and regulatory challenges in final applications.
High-quality factory supply chains prioritize the removal of inorganic salts and isomeric byproducts. During the baking phase, temperature control is critical; excessive heat can lead to decomposition, while insufficient heat results in incomplete conversion. The resulting product is typically a white powder with a faint purple tinge or grayish-white flat crystals. Maintaining this physical appearance is often the first visual indicator of quality before laboratory analysis confirms the chemical specifications.
Interpreting COA Data and Assay
When reviewing a COA for a dye intermediate, the assay percentage is the most critical metric. Standard industrial specifications often require a minimum assay of 99.0% on a dried basis. However, sophisticated buyers look beyond the primary assay to understand the impurity profile. The molecular weight is fixed at 173.19 g/mol, and deviations in titration results can indicate the presence of moisture or inorganic sulfates.
Physical properties listed on the COA provide further insight into the material's handling characteristics. For instance, the substance is known to decompose without melting at approximately 550°F (288°C). This thermal stability profile is essential for processors who may subject the material to elevated temperatures during subsequent synthesis steps. Furthermore, solubility data indicates that the compound is sparingly soluble in cold water (less than 1 mg/mL at 68°F) but dissolves readily in hot water and alkaline solutions. This behavior is consistent with its zwitterionic nature.
For buyers evaluating technical datasheets, comparing these physical constants against standard references is a best practice. When sourcing high-purity 4-Aminobenzenesulfonic Acid, buyers should verify that the specific gravity aligns with expected values, typically around 1.485 at 77°F. Discrepancies here often signal contamination or improper drying during the final crystallization stage.
Technical Specification Table
| Parameter | Specification Standard | Typical Result |
|---|---|---|
| Chemical Name | 4-Aminobenzenesulfonic Acid | Conforms |
| CAS Number | 121-57-3 | 121-57-3 |
| Molecular Formula | C6 H7 N O3 S | C6 H7 N O3 S |
| Assay (Dried Basis) | ≥ 99.0% | 99.2% - 99.5% |
| Decomposition Point | ~288°C (550°F) | 288°C |
| Appearance | White to Grayish Powder | White Powder |
| Water Solubility | Slight in Cold, Soluble in Hot | Conforms |
Impurity Limits for Free Aniline
Safety and regulatory compliance are inextricably linked to impurity profiles. The most critical impurity to monitor is free aniline. Due to the toxicity associated with aniline derivatives, strict limits are enforced in many jurisdictions. A robust COA will explicitly state the maximum permissible limit for free aniline, often in the range of parts per million (ppm). Exceeding these limits can classify the material as hazardous beyond standard handling protocols.
Protective Action Criteria (PAC) data indicates specific exposure thresholds. For example, PAC-3 levels are established at 2400 mg/m3, highlighting the need for proper ventilation during handling. While the compound itself is a local irritant, decomposition can evolve toxic fumes, particularly upon contact with acids or when heated excessively. Therefore, storage precautions mandate keeping the chemical away from mineral acids and bases. Refrigerated temperatures are often recommended for long-term stability to prevent degradation.
From a health hazard perspective, the material can cause irritation to the skin, eyes, and mucous membranes. Proper personal protective equipment (PPE), including NIOSH-approved respirators with organic vapor/acid gas cartridges, is essential during weighing and dilution processes. In the event of a spill, isolation distances should be maintained, and contaminated materials must be sealed in vapor-tight plastic bags for disposal. These safety parameters are often reflected in the regulatory section of a comprehensive COA.
Bulk Procurement and Supply Chain Reliability
Securing a reliable supply chain for chemical raw materials is vital for continuous industrial operation. Fluctuations in bulk price are often tied to the availability of aniline and sulfuric acid feedstocks. Partnering with a stable manufacturer ensures that production schedules are not disrupted by raw material shortages. NINGBO INNO PHARMCHEM CO.,LTD. maintains robust inventory levels to support large-scale procurement needs, ensuring that clients receive material that meets consistent industrial purity specifications batch after batch.
Logistics also play a crucial role in maintaining quality. The compound should be transported in conditions that prevent moisture uptake, as hygroscopic behavior can affect the assay weight. Upon receipt, quality control teams should verify the lot number against the provided COA. For specialized applications, such as Sulfanilic Acid Monohydrate variants or specific particle size distributions, custom specifications can often be negotiated directly with the manufacturer.
In conclusion, the technical integrity of 4-aminobenzenesulfonic acid is defined by its assay, impurity profile, and physical constants. By prioritizing suppliers who provide transparent COA data and adhere to strict safety standards, procurement managers can mitigate risk and optimize their synthesis routes. Whether for use as a dye intermediate or a specialized chemical building block, understanding these specifications is the foundation of successful industrial chemistry.