Overview
Sodium beta-naphthoquinone-4-sulfonate (CAS 521-24-4 ), commonly abbreviated as NQS, is a water-soluble quinone reagent used in analytical and pharmaceutical chemistry.
It functions as a chromogenic derivatizing agent, reacting with primary and secondary amines to produce colored complexes measurable by spectrophotometry for various applications.
NQS is used in pharmaceutical quality control for the colorimetric determination of amino-containing active pharmaceutical ingredients, including sulfonamides and aminoglycosides.
This enables quantitative assay development without chromatographic separation. In clinical and biochemical analysis, it supports the detection and quantification of amino acids.
Biotechnology workflows use NQS as a labeling reagent for amine-functionalized compounds, supporting assay development and compound characterization at research and pilot scale.
It also appears in the development of stability-indicating methods, where its selective reactivity with amine groups helps identify degradation products in drug formulations.
Sodium beta-naphthoquinone-4-sulfonate is supplied as a solid powder, typically in high-purity grades suited for analytical and pharmaceutical research applications.
Material is generally available at reagent or research grade, with purity specifications commonly at 97% or higher. Packaging ranges from small laboratory quantities to bulk orders.
Contact us for supply of Sodium beta-naphthoquinone-4-sulfonate
Physical Properties
| Melting Point | 287 °C (decomp) |
| Appearance | powder |
| Color | dark orange |
| Odor | Odorless |
| Form | solid |
| Water Solubility | Soluble in water and acetone. Slightly soluble in alcohol and ethanol. Insoluble in chloroform. |
Safety & Handling
Warning GHS07 Hazard Statements H315 Causes skin irritation H319 Causes serious eye irritation H335 May cause respiratory irritation Precautionary Statements P261 Avoid breathing dust/fume/gas/mist/vapours/spray. P264 Wash … thoroughly after handling. P271 Use only outdoors or in a well-ventilated area. P280 Wear protective gloves/protective clothing/eye protection/face protection. P319 Get medical advice/attention if you feel unwell. P321 Specific treatment (see … on this label). P405 Store locked up. P501 Dispose of contents/container in accordance with local regulations. P264+P265 Wash … thoroughly after handling. P302+P352 IF ON SKIN: Wash with plenty of water. P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing. P332+P317 Get emergency medical help. P337+P317 If eye irritation persists: Get medical advice/attention. Get emergency medical help. P362+P364 Take off contaminated clothing and wash it before reuse. P403+P233 Store in a well-ventilated place. Keep container tightly closed. P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
Trade & Regulatory
| HS Code | 29147000 |
| WGK (Germany) | 3 |
Other Names
Related Products
Chemical Properties
- CAS Number
- 521-24-4
- EC Number
- 208-308-9
- Mol. Weight
- 260.20
- HS Code
- 29147000
- Category
- Salts & Minerals