Buying a commodity solvent and buying a coenzyme are different jobs. A coenzyme lot is a hygroscopic, oxidation-sensitive biochemical whose usable content depends on the assay method, whose water content quietly changes what you receive, and whose documentation is often the thing that decides whether it can enter your process at all. This article sets out the five items that should appear on every coenzyme enquiry, and the checks worth running when the drum arrives.
1. Why coenzymes are not bought like other chemicals
| Feature | Commodity chemical | Coenzyme |
|---|---|---|
| Assay | One accepted method, one basis | HPLC or enzymatic; dry basis or as-received; the two answers differ |
| Moisture | Secondary | Primary – hygroscopic, and water is not coenzyme |
| Identity risk | Low | Same name covers free acid and three different salts with different CAS numbers |
| Stability | Usually robust | Oxidation, light, acid and freeze-thaw all matter |
| Documentation | Standard SDS | COA plus method statement, solvent residues, microbial and endotoxin data on request |
2. Item one: assay – and the basis behind it
“98%” on its own is not a specification. Ask three questions: which method (HPLC or enzymatic), which basis (dry or as-received), and which figure for the oxidised or reduced counterpart. For a reduced coenzyme such as NADH, an HPLC purity figure and an enzymatic activity figure answer different questions, and a lot can pass one while failing the other. For the oxidised forms the reverse question applies: how much has already converted, and is that reported?
3. Item two: water content and the impurity profile
| Item | Typical relevance | Why to ask for it |
|---|---|---|
| Water content / loss on drying | All coenzymes | Converts a dry-basis assay into what you actually receive |
| Residual solvents | Ethanol, sometimes methanol or acetone | Isolation is usually from aqueous alcohol; limits matter for pharmaceutical and food customers |
| Heavy metals | All grades | Standard for regulated applications; also a rough process-quality signal |
| Sodium content | Salt forms | Confirms which salt you were sent – a partly exchanged salt can still hit the HPLC figure |
| Endotoxin / microbial | Cell-based work, IVD reagents | Almost never stated unless requested; expensive to discover late |
4. Item three: the documentation package
- COA per lot, with the lot number matching the label and the packing list.
- Method statement: how the assay was run, and on what basis. A COA without a method is a number without meaning.
- SDS in the language your site requires.
- Third-party testing on request – worth doing on the first lot of a new supplier rather than on every lot afterwards.
- Regulatory position statement for the intended use and destination, especially for the precursor grades where the rules differ by market.
5. Item four: cold chain and packaging
Powder coenzymes are usually shipped ambient for short transits and stored at -20 °C; aqueous solutions need 2-8 °C and no freeze-thaw. Agree three things before the price is fixed: the shipping temperature, the pack size (it should match a working batch, not just the best freight rate), and what happens if the shipment is delayed in summer. A drum of solution that sat on a dock for three days is a stability question, not a logistics detail.
6. Item five: traceability and supplier qualification
Ask for the manufacturer’s name and lot numbering, not only the trader’s reference. For a regulated application you will eventually need to audit or at least document the manufacturing site; establishing that at enquiry stage is far cheaper than retrofitting it. If a supplier cannot say where the material was made, treat that as a qualification gap rather than a confidentiality arrangement.
7. An enquiry template that gets a comparable answer
| Field | Example entry |
|---|---|
| Product and CAS | NADP disodium salt, CAS 24292-60-2 |
| Form | Powder, or 75% min aqueous solution |
| Assay requirement | 98.0% min, dry basis, HPLC |
| Quantity | 25 kg for the first order, 200 kg per year thereafter |
| Documentation | COA with method statement; endotoxin figure required before approval |
| Shipping | FOB Shanghai; 2-8 °C required for the solution |
| End use and destination | Biocatalysis raw material, Germany |
Filling in seven fields removes most of the guesswork from a quotation, and it makes two suppliers’ offers comparable without a second round of questions.
8. Incoming goods checks worth doing
| Check | Method | Fail signature |
|---|---|---|
| Identity | Compare CAS and salt form on label, COA and packing list | Free acid sent against a disodium order – dissolves slowly, different sodium load |
| Content as received | Assay corrected by measured water content | Headline assay met, delivered content short |
| Moisture | Karl Fischer or loss on drying | Exceeds the specification on a hygroscopic lot |
| Appearance | Visual against the specification | Discoloured powder – oxidation or metal contamination |
| Function | Small-scale enzyme or assay run | Works on paper, underperforms in the reaction – usually oxidised content |
9. Cost per mole, not cost per kilogram
Across this family the molecular weight ranges from 663.4 (NAD) to 833.3 (NADPH tetrasodium), so equal prices per kilogram are not equal prices per mole of coenzyme. Correct for molecular weight, for assay and for water content before comparing, then add freight – which for a 75-85% solution means paying to ship water. On a catalytically regenerated process the coenzyme cost per kilogram of product is small, and the dominant cost is the regeneration substrate; on a stoichiometric assay reagent the coenzyme is the cost, and a two-point difference in delivered content is a two-point swing in the cost per test.
10. Packaging and supply
Coenzymes are supplied in foil-lined bags or fibre drums with an inner liner for powder, and in HDPE drums or flexibags for solution, sized to the batch you actually run. Every lot arrives with a certificate of analysis and a safety data sheet, and PolyBlueChem can arrange third-party testing, a method statement and cold-chain shipment where the application requires it. The most useful thing a buyer can do is state the end use and the regulatory framework up front – the documentation package and the grade follow from that, and quoting before it is settled usually means quoting twice.
Related reading
- NAD, NADH, NADP and NADPH: forms, salt types and bulk supply
- NAD in three forms: aqueous solution, biotransformation grade and food grade
- NADH: stability, diagnostic assays and biocatalytic use
Products in this family
- NAD (CAS 53-84-9) – 85% min solution, 98% min and 99% min powders
- NADP disodium salt (CAS 24292-60-2) – 75% min solution and 98% min powder
- NADH disodium salt (CAS 606-68-8) – assay 98% min
- beta-NMN (CAS 1094-61-7) – assay 99% min
- Nicotinamide riboside chloride (CAS 23111-00-4) – purity 98% min
PolyBlueChem supplies NAD, NADH, NADP and NADPH in the salt form and grade you specify, plus β-NMN and nicotinamide riboside chloride, with per-batch COA and SDS and FOB/CIF delivery. Send the seven enquiry fields above and you will get a quotation you can compare line by line.