Molekula
Calmagite
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 2000 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Calmagite is a metallochromic indicator used in complexometric titrations, particularly for detecting calcium and magnesium ions. It appears as a dark red crystalline powder. At about pH 10 the free indicator is blue and turns wine-red when bound to magnesium or calcium ions, so at the titration endpoint, when EDTA removes the metal, the solution changes from red to blue. Available in powder form with a molecular weight of 358.37 g/mol, CAS number 3147-14-6, and stored at ambient temperatures. Signal word: Warning. Molekula supplies Calmagite from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
Example image for illustration only. Other packaging and pack sizes are available.
Pricing & pack sizes
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 — £64.80 per pack ex VAT · £77.76 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 brown/ black powder |
| Melting Point | 329-331°C |
| Loss on Drying | ≤10% |
| Lambda max | 600-615 |
| pH transition interval | 7.1 (red) to 9.1 (blue) |
| Specific Extinction (1%/1cm) | >300 |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Acid |
Identification
| Property | Value |
|---|---|
| SKU | 28767001 |
| CAS Number | 3147-14-6 |
| IUPAC Name | 3-hydroxy-4-[(2-hydroxy-5-methylphenyl)diazenyl]naphthalene-1-sulfonic acid |
| EC Number | 221-563-0 |
| Molecular Formula | HOC10H5[N=NC6H3(OH)CH3]SO3H |
| Molecular Weight | 358.37 |
| Exact Mass | 358.0623 |
| SMILES | CC1=CC(=C(C=C1)O)N=NC2=C(C=C(C3=CC=CC=C32)S(=O)(=O)O)O |
| InChIKey | VBRNLOQCBCPPHL-UHFFFAOYSA-N |
| InChI | InChI=1S/C17H14N2O5S/c1-10-6-7-14(20)13(8-10)18-19-17-12-5-3-2-4-11(12)16(9-15(17)21)25(22,23)24/h2-9,20-21H,1H3,(H,22,23,24) |
| PubChem CID | 2530 |
| REACH Code | Y113 |
| TSCA Listed | Yes |
| Tariff Code | 2927000090 |
Safety & GHS
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Health Hazard
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
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P302+352 IF ON SKIN: Wash with soap and water
- P304+340 IF INHALED: Remove victim to fresh air and keep at rest in a position comfortable for breathing
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Spanish.
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.
Synonyms
- 1-(1-Hydroxy-4-methyl-2-phenylazo)-2-naphthol-4-sulfonic acid
- 1-Naphthalenesulfonic acid, 3-hydroxy-4-[(2-hydroxy-5-methylphenyl)azo]-
- 1-Naphthalenesulfonic acid, 3-hydroxy-4-[(6-hydroxy-m-tolyl)azo]-
- 3-Hydroxy-4-((6-hydroxy-m-tolyl)azo)-1-naphthalenesulfonic acid
- 3-Hydroxy-4-(2-hydroxy-5-methyl- phenylazo)-1-naphthalenesulfonic acid
- 3-Hydroxy-4-(6-hydroxy-m-tolylazo)naphthalene-1-sulphonic acid
- 3-hydroxy-4-[(2-hydroxy-5-methylphenyl)diazenyl]naphthalene-1-sulfonic acid
- 3-hydroxy-4-[(2-hydroxy-5-methylphenyl)diazenyl]naphthalenesulfonic acid
- CALMAGITE [METAL INDICATOR FOR CA, MG ETC.]
- Calmagite, Indicator Grade
Frequently asked questions
What is Calmagite used for?
Calmagite is primarily used as a metal ion indicator in complexometric titrations, especially for detecting calcium and magnesium ions in water analysis.
What is the chemical formula and molecular weight of Calmagite?
The formula is HOC10H5[N=NC6H3(OH)CH3]SO3H with a molecular weight of 358.37 g/mol.
How should Calmagite be stored?
Calmagite should be stored at ambient temperature, protected from light and moisture.
What grade of Calmagite does Molekula supply?
Molekula supplies Calmagite in analytical grade for laboratory use.
Can Molekula supply Calmagite in bulk quantities?
Yes, Molekula can supply Calmagite in bulk quantities—please contact our sales team for volume pricing and availability.
What documentation comes with a Calmagite order?
Each order includes a Certificate of Analysis (CoA) and Safety Data Sheet (SDS) compliant with GHS standards.
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.