Molekula
Potassium sodium tartrate tetrahydrate (Rochelle Salt), USP Grade
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
Potassium sodium tartrate tetrahydrate, also known as Rochelle Salt, is a double salt of potassium and sodium tartrate used primarily in pharmaceuticals, food processing, and analytical chemistry as a buffering agent, sequestrant, and in Fehling’s solution for sugar testing. It meets USP Grade standards for purity and consistency. This chemical has a CAS number of 6381-59-5, with the molecular formula C4H4KNaO6 and a molecular weight of 210.16. It is stable at ambient storage conditions and carries no signal word for hazard classification.
Molekula supplies Potassium sodium tartrate tetrahydrate (Rochelle Salt), USP Grade at ≥99% purity in 500 g packs, from £50.40 inc. VAT. It is in stock for same-day dispatch. Every batch ships with a certificate of analysis, and a safety data sheet is available. Larger quantities, up to multi-tonne, are quoted on request.
Example image for illustration only. Other packaging and pack sizes are available.
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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500 g — £42.00 per pack ex VAT · £50.40 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 | Off-white to white crystals |
| Grade | USP |
| Assay | ≥99% |
| Insoluble Matter | ≤0.05% |
| pH (5% sol) | 7.0-8.0 |
| Sulphates (SO4)(2-) | ≤0.05% |
| Heavy Metal (As,Pb) | ≤0.001% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Identification
| Property | Value |
|---|---|
| SKU | 90025401 |
| CAS Number | 6381-59-5 |
| Molecular Formula | C4H4KNaO6 |
| Molecular Weight | 210.16 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 2918.13.3000 |
| Tariff Code | 29181300 |
Safety & GHS
Precautionary statements
- P280 Wear protective gloves/protective clothing/eye protection/face protection
Documents
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 potassium sodium tartrate tetrahydrate (Rochelle Salt) commonly used for?
It is used as a component of Fehling's solution and the biuret reagent, in food processing as a stabilizer, and in laboratory applications for buffer solutions and qualitative analysis.
What is the chemical formula and molecular weight of Rochelle Salt?
The chemical formula is C₄H₄KNaO₆, and the molecular weight is 210.16 g/mol.
What grade of Rochelle Salt does Molekula supply, and is it suitable for pharmaceutical use?
Molekula supplies USP Grade Rochelle Salt, which meets pharmaceutical standards for use in food, pharmaceuticals, and laboratory applications.
How should Rochelle Salt be stored?
Store in a tightly sealed container at ambient temperature, away from moisture and strong oxidizing agents.
Can Molekula supply Rochelle Salt in bulk quantities?
Yes, Molekula can provide Rochelle Salt in bulk, with quantities tailored to your specific requirements—please contact us for details.
What documentation is provided with an order of Rochelle Salt?
Each order includes a Certificate of Analysis (CoA), Material Safety Data Sheet (MSDS), and batch-specific documentation for traceability.
Where can I buy Potassium sodium tartrate tetrahydrate (Rochelle Salt), USP Grade?
Directly from Molekula, which lists Potassium sodium tartrate tetrahydrate (Rochelle Salt), USP Grade in 500 g packs from £50.40 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.