Buying 2-chloronicotinic acid (CAS 2942-59-8) well means understanding the specification sheet, the impurities that matter, and how to verify quality on arrival. This purchasing guide covers each COA parameter and the supplier questions worth asking.
1. Reading the Specification
| Parameter | Value | Why it matters |
|---|---|---|
| Appearance | White crystalline powder | Visual QC |
| Assay (HPLC) | 99.5% min | Active content for dosing |
| 6-Chloronicotinic acid | 0.10% max | Regioisomer impurity, affects downstream reactions |
| 2-CNA dimer | 0.10% max | Dimer impurity from process |
| Correlated each other impurity | 0.10% max | Individual related-substance limit |
| Sulphate | 0.10% max | Inorganic residue |
| Loss on drying | 0.30% max | Moisture/solvent |
| Residue on ignition | 0.20% max | Non-volatile metals/ash |
| Melting range | >177 °C (decomp.) | Identity and purity indicator |
| Solution clarity | Clear in 0.5 mol/L NaOH | Dissolution quality |
2. What a Complete COA Should Show
- Batch number, production and analysis dates.
- HPLC assay with method reference.
- Each impurity line measured (not just “conforms”).
- Loss on drying, residue on ignition, sulphate.
- Test methods and equipment used.
3. Verification on Arrival
- Check appearance and solution clarity first (fast visual pass/fail).
- Run HPLC assay against a reference standard if your lab can; at minimum confirm assay and isomer impurity.
- Confirm loss on drying if the material will be weighed into moisture-sensitive reactions.
4. Packaging and Storage
- 25 kg fibre drums or bags with PE liner; custom pack sizes for trial batches.
- Store sealed, cool and dry; avoid moisture, strong bases and oxidizers.
- Reseal after sampling to prevent moisture pick-up.
5. Supplier Checklist
- Can they guarantee isomer purity (6-chloronicotinic acid ≤0.10%) batch to batch?
- Do they provide batch COA with measured impurity values?
- Can they supply custom derivatives (esters, amides, 2-substituted nicotinates)?
- Do they have ISO/GMP documentation for pharma use?
6. FAQ
What is the difference between 2- and 6-chloronicotinic acid on a COA?
They are regioisomers with different reactivity; the COA should list 6-chloronicotinic acid as a controlled impurity ≤0.10%.
Can I order small quantities for trials?
Yes – trial packs are available; contact us for details.
7. References and Further Reading
- Supplier COA and MSDS for the specific grade quoted.
This article is published for industrial and technical reference by PolyblueChem. Verify against the supplier’s COA and applicable standards.
See our 2-chloronicotinic acid chemistry and production guide and the pharma application guide. PolyblueChem supplies 2-chloronicotinic acid (CAS 2942-59-8) – contact us for specifications and quotations.