Certificate of Analysis and technical specification for 4,4'-Diaminostilbene-2,2'-Disulfonic Acid (DASDA) — CAS 81-11-8. Applies to all consignments of this product and grade.
| Product Name | 4,4'-Diaminostilbene-2,2'-Disulfonic Acid (DASDA) |
|---|---|
| C.A.S. Number | 81-11-8 |
| Product Category | Dyes & Dye Intermediates |
| Product Group | Stilbene Intermediates |
| Grade / Standard | ≥98% Technical |
| Physical Form | Grey to light yellow powder |
| Country of Origin | India |
| Packing | Standard export packing — bags, drums, carboys, IBC or ISO tank as applicable |
| Storage | Cool, dry, well-ventilated place in tightly closed original packing |
| S. No. | Test Parameter | Specification | Typical Result | Method |
|---|---|---|---|---|
| 1 | Description | Grey to light yellow powder | Complies | Visual |
| 2 | Identification | Conforms to the structure of the substance | Complies | FTIR / Chemical test |
| 3 | Solubility | As per specification | Complies | Visual / Monograph |
| 4 | Assay | Not less than 98.0 % w/w | 98.73 | Spectrophotometry |
| 5 | Shade | Matching approved standard | Matches standard | Visual / Spectrophotometric |
| 6 | Strength vs. Standard | 100 ± 3 % | 99.8 % | Spectrophotometry |
| 7 | Moisture | Not more than 5.0 % w/w | 3.17 | Gravimetry |
| 8 | Matter Insoluble in Water | Not more than 1.0 % w/w | 0.178 | Gravimetry |
| 9 | Solubility in Water at 60 °C | Not less than 80 g/L | 94 g/L | In-house method |
| 10 | Light Fastness (ISO 105-B02) | Grade 5 – 6 minimum | Grade 5 | ISO 105-B02 |
| 11 | Wash Fastness (ISO 105-C06) | Grade 4 – 5 minimum | Grade 5 | ISO 105-C06 |
This document sets out the standard specification for 4,4'-Diaminostilbene-2,2'-Disulfonic Acid (DASDA) and applies to all consignments of this grade. It is not a lot-specific release document; a lot-specific certificate carrying the analysis of the material actually shipped is issued with each consignment. Scapex Exports supplies against customer-specified assay limits and pharmacopoeial standards — send your specification sheet and we will confirm compliance before order.
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