Molekula
Hydroxy naphthol blue disodium salt (C20H12N2O11S3Na2)
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 1999 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Hydroxy naphthol blue disodium salt is a chromogenic indicator used in complexometric titrations, particularly for detecting metal ions like calcium and magnesium. It appears as a dark blue crystalline powder and is soluble in water. CAS: 165660-27-5, Molecular Formula: C20H12N2O11S3Na2, Molecular Weight: 598.49 g/mol, Storage: Ambient, Signal Word: Warning.
Molekula supplies Hydroxy naphthol blue disodium salt (C20H12N2O11S3Na2) in 25 g packs, from £44.28 inc. VAT. It is in stock for same-day dispatch. Every batch ships with a certificate of analysis, and safety data sheets are available in 5 languages. Larger quantities, up to multi-tonne, are quoted on request.
Example image for illustration only. Other packaging and pack sizes are available.
Often bought together
Pricing & pack sizes
In stock — same-day dispatch
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.
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25 g — £36.90 per pack ex VAT · £44.28 inc. VAT
Need a different quantity or pack?
Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.
Prices exclude VAT/sales tax and shipping.
Specifications
| Property | Value |
|---|---|
| Appearance | Dark blue powder or crystals |
| Loss on Drying | ≤ 6.0% |
| Absorptivity | 350 - 500, 1%/ 1cm in ammonia buffer pH 12.0 +2ml 0.05 M.E.T.D.A at λmax. 648.0nm |
| Identification (RAMAN) | Conforms to Reference |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Identification
| Property | Value |
|---|---|
| SKU | 90030492 |
| CAS Number | 165660-27-5 |
| IUPAC Name | disodium;3-hydroxy-4-[(2-hydroxy-4-sulfonatonaphthalen-1-yl)diazenyl]-7-sulfonaphthalene-2-sulfonate |
| Molecular Formula | C20H12N2O11S3Na2 |
| Molecular Weight | 598.49 |
| Exact Mass | 597.9399 |
| SMILES | C1=CC=C2C(=C1)C(=CC(=C2N=NC3=C4C=CC(=CC4=CC(=C3O)S(=O)(=O)[O-])S(=O)(=O)O)O)S(=O)(=O)[O-].[Na+].[Na+] |
| InChIKey | WPDDXLRAJOPBIR-UHFFFAOYSA-L |
| InChI | InChI=1S/C20H14N2O11S3.2Na/c23-15-9-16(35(28,29)30)13-3-1-2-4-14(13)18(15)21-22-19-12-6-5-11(34(25,26)27)7-10(12)8-17(20(19)24)36(31,32)33;;/h1-9,23-24H,(H,25,26,27)(H,28,29,30)(H,31,32,33);;/q;2*+1/p-2 |
| PubChem CID | 135889525 |
| REACH Code | Y110 |
| Tariff Code | 29270000 |
Safety & GHS
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Health Hazard
GHS07
Hazard statements
- H319 Causes serious eye irritation
Precautionary statements
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
- P337+313 If eye irritation persists get medical advice/attention
Documents
Safety Data Sheets (SDS)
Available in English, English (US), French, German, Italian.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Quality certificates
Molekula Group is certified to ISO 9001:2015 (quality) and ISO 14001:2015 (environmental management), audited by a UKAS-accredited body. Both certificates are valid to 17 May 2028.
Synonyms
No alternate names recorded for this product.
Frequently asked questions
What is hydroxy naphthol blue disodium salt used for?
This dye is used as a metallochromic indicator in complexometric (EDTA) titrations, particularly for the determination of calcium at about pH 12–13, where the colour changes from red (metal complex) to blue (free indicator) at the endpoint. It is also used for visual, colorimetric detection of loop-mediated isothermal amplification (LAMP) reactions, where depletion of magnesium ions shifts the colour from violet to sky blue.
What is the molecular formula and molecular weight of hydroxy naphthol blue disodium salt?
The molecular formula is C₂₀H₁₂N₂O₁₁S₃Na₂, and the molecular weight is 598.49 g/mol.
How should hydroxy naphthol blue disodium salt be stored?
Store at ambient temperature in a tightly sealed container, away from moisture and direct sunlight.
What grades or purities of hydroxy naphthol blue disodium salt does Molekula offer?
Our hydroxy naphthol blue disodium salt is supplied to a specification covering appearance (dark blue powder or crystals), loss on drying (≤ 6.0%), absorptivity (350–500, 1%/1cm in ammonia buffer pH 12.0 with 2 ml 0.05 M EDTA at λmax 648.0 nm) and identification by RAMAN conforming to reference.
Can Molekula supply hydroxy naphthol blue disodium salt in bulk quantities?
Yes, we can accommodate bulk orders—please contact our sales team for pricing and lead time details.
What documentation comes with an order of hydroxy naphthol blue disodium salt?
Each order includes a Certificate of Analysis (CoA), Material Safety Data Sheet (MSDS), and batch-specific documentation for traceability.
Where can I buy Hydroxy naphthol blue disodium salt (C20H12N2O11S3Na2)?
Directly from Molekula, which lists Hydroxy naphthol blue disodium salt (C20H12N2O11S3Na2) in 25 g packs from £44.28 inc. VAT, with a certificate of analysis for every batch. Larger quantities are quoted on request. Molekula's offices: United Kingdom, France, Spain, Germany, Italy, United States and China.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.