Molekula
Xylenol Blue
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
Xylenol Blue is a sulfonephthalein dye used primarily as an acid–base pH indicator, with color transitions at about pH 1.2–2.8 (red to yellow) and pH 8.0–9.6 (yellow to blue), and as a pH indicator in biochemical assays. It appears as a dark green powder and is soluble in water and ethanol. CAS: 125-31-5, Molecular Formula: C23H22O5S, Molecular Weight: 410.48 g/mol. Store at ambient temperature. Signal word: Warning. Molekula supplies Xylenol Blue 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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5 g — £46.50 per pack ex VAT · £55.80 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 powder |
| Loss on Drying | 1% max |
| Specific absorbance | (E1%/1cm): 807 (@594nm in buffer) |
| Lambda max | 594nm (in buffer) |
| Colour Change | pH 8.0 (yellow) - pH 9.6 (blue) |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Identification
| Property | Value |
|---|---|
| SKU | 21036397 |
| CAS Number | 125-31-5 |
| IUPAC Name | 4-[3-(4-hydroxy-2,5-dimethylphenyl)-1,1-dioxo-2,1lambda6-benzoxathiol-3-yl]-2,5-dimethylphenol |
| EC Number | 204-736-5 |
| Molecular Formula | C23H22O5S |
| Molecular Weight | 410.48 |
| Exact Mass | 410.1188 |
| SMILES | CC1=CC(=C(C=C1O)C)C2(C3=CC=CC=C3S(=O)(=O)O2)C4=C(C=C(C(=C4)C)O)C |
| InChIKey | MGUKYHHAGPFJMC-UHFFFAOYSA-N |
| InChI | InChI=1S/C23H22O5S/c1-13-11-20(24)15(3)9-18(13)23(19-10-16(4)21(25)12-14(19)2)17-7-5-6-8-22(17)29(26,27)28-23/h5-12,24-25H,1-4H3 |
| PubChem CID | 67172 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 29349944 |
| Tariff Code | 2934999090 |
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
- P308+313 IF exposed or concerned: Get medical advice/attention
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Portuguese, 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
- 1,4-dimethyl-5-hydroxybenzenesulfonephthalein
- 1,4-Dimethyl-5-hydroxybenzenesulfonphthalein
- 2,5-Xylenol, 4,4'-(3H-2,1-benzoxathiol-3-ylidene)di-, S,S-dioxide
- p-Xylenesulfonephthalein
- p-Xylenol Blue
- p-Xylenolsulfonephthalein
- p-Xylenolsulfonphthalein
- p-Xylenolsulfophthalein
- Phenol, 4,4'-(3H-2,1-benzoxathiol-3-ylidene)bis(2,5-dimethyl-, S,S-dioxide
- XYLENOL BLUE, P-
Frequently asked questions
What is Xylenol Blue used for?
Xylenol Blue is primarily used as a pH indicator in analytical chemistry, with transitions at about pH 1.2–2.8 (red to yellow) and pH 8.0–9.6 (yellow to blue).
What is the chemical formula and molecular weight of Xylenol Blue?
The formula is C23H22O5S with a molecular weight of 410.48 g/mol.
How should Xylenol Blue be stored?
Store at ambient temperature, protected from light and moisture.
What grade of Xylenol Blue is available?
Available in analytical grade for laboratory use.
Can Molekula supply Xylenol Blue in bulk?
Yes, Molekula can supply Xylenol Blue in bulk quantities—please contact sales for details.
What documentation comes with an order of Xylenol Blue?
Each order includes a Certificate of Analysis (CoA) and Safety Data Sheet (SDS).
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.