Molekula
Bromocresol Purple
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
Bromocresol Purple is a pH indicator dye used in analytical chemistry and biological assays to detect acid-base transitions. It appears purple in basic solutions and yellow in acidic conditions. Available in powder form with a molecular weight of 540.22 g/mol, CAS number 115-40-2, and molecular formula C21H16Br2O5S. Store at ambient temperature. Signal word: Warning. Molekula supplies Bromocresol Purple 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.
Often bought together
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 — £71.20 per pack ex VAT · £85.44 inc. VAT
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100 g — £160.00 per pack ex VAT · £192.00 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 | Pink/Purple Powder |
| Grade | ACS Grade |
| Loss on Drying | ≤ 1.0% |
| Dye Content | ≥ 95% |
| Transition Range | pH: 5.2 (yellow) , pH: 6.8 (purple) |
| Absorption maximum (pH 5.2) max | 431 nm |
| Absorption maximum (pH 6.8) max | 589 nm |
| Absorptivity (A 1% in 1cmcell, pH 5.2 max | 437 |
| Absorptivity (A 1% in 1cmcell, pH 6.8 max | 1057 |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Literature values
Published physical properties of the substance, not batch specifications.
| Property | Value |
|---|---|
| Appearance | Minute, slightly yellow crystals |
| Melting Point | 241.5 °C |
| Solubility (other solvents) | Soluble in alcohol, dilute alkalies |
| pKa | pKa = 6.3 |
Source: PubChem CID 8273 (HSDB)
Identification
| Property | Value |
|---|---|
| SKU | 46156907 |
| CAS Number | 115-40-2 |
| IUPAC Name | 2-bromo-4-[3-(3-bromo-4-hydroxy-5-methylphenyl)-1,1-dioxo-2,1lambda6-benzoxathiol-3-yl]-6-methylphenol |
| EC Number | 204-087-8 |
| Molecular Formula | C21H16Br2O5S |
| Molecular Weight | 540.22 |
| Exact Mass | 539.9065 |
| SMILES | CC1=CC(=CC(=C1O)Br)C2(C3=CC=CC=C3S(=O)(=O)O2)C4=CC(=C(C(=C4)C)O)Br |
| InChIKey | ABIUHPWEYMSGSR-UHFFFAOYSA-N |
| InChI | InChI=1S/C21H16Br2O5S/c1-11-7-13(9-16(22)19(11)24)21(14-8-12(2)20(25)17(23)10-14)15-5-3-4-6-18(15)29(26,27)28-21/h3-10,24-25H,1-2H3 |
| PubChem CID | 8273 |
| REACH Code | Y113 |
| HTS Code | 2934999001 |
| 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
- P332+313 IF skin irritation occurs: Get medical advice/attention
- P337+313 If eye irritation persists 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
- 3,3-Bis(3-bromo-4-hydroxy-5-methylphenyl)-3H-benzo[c][1,2]oxathiole 1,1-dioxide
- 4,4'-(3H-2,1-BENZOXATHIOL-3-YLIDENE)BIS(2-BROMO-6-METHYLPHENOL) S,S-DIOXIDE
- 5,5'-Dibromo-o-cresolsulfonphthalein
- BROMCRESOL PURPLE
- C21H16Br2O5S
- Indicator bromocresol purple
- Phenol, 4,4'-(1,1-dioxido-3H-2,1-benzoxathiol-3-ylidene)bis[2-bromo-6-methyl-
- Phenol, 4,4'-(3H-2,1-benzoxathiol-3-ylidene)bis(2-bromo-6-methyl)-, S,S-dioxide
- Purple, Bromcresol
- Purple, Bromocresol
Frequently asked questions
What is Bromocresol Purple used for?
Bromocresol Purple is primarily used as a pH indicator in analytical chemistry, particularly in the range of pH 5.2 to 6.8, where it changes from yellow to purple.
What is the chemical formula and molecular weight of Bromocresol Purple?
The chemical formula is C21H16Br2O5S, and the molecular weight is 540.22 g/mol.
How should Bromocresol Purple be stored?
It should be stored at ambient temperature, protected from light and moisture.
What grade of Bromocresol Purple does Molekula supply?
Molekula supplies Bromocresol Purple in analytical grade.
Can Molekula supply Bromocresol Purple in bulk?
Yes, Molekula can supply Bromocresol Purple in bulk quantities—please contact our sales team for details.
What documentation comes with a purchase of Bromocresol Purple?
Each order includes a Certificate of Analysis (CoA) and Safety Data Sheet (SDS) with the shipment.
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.