Impurity and isotope-labelled reference standards, documented lot by lot.
CATO manufactures the hard-to-source compounds analytical laboratories actually need — nitrosamine and genotoxic impurities, metabolites, deuterated and 13C-labelled standards. Search 466 compounds by CAS number or name; every lot ships with its own certificate of analysis.
466compounds in the launch catalogue
347searchable CAS numbers
211items with stock on hand
COAissued per lot, not per product
Certificate per lot
Every batch ships with its own COA and MSDS, retrieved by lot number.
ISO 17034 · ISO 9001
Quality system covering production and certification of reference materials.
Worldwide shipping
Ambient, ice-pack or dry-ice packing, with customs documentation.
Custom synthesis
Not in the catalogue? Send the structure and we will quote it.
In stock or on synthesis
Frequently requested impurities, metabolites and labelled standards from the current catalogue. Each product page carries the pack sizes, lead time and documentation.
Find every impurity of one drug substance
Most enquiries arrive as “do you have the full set for this API?”. Each hub lists the pharmacopoeial impurities, non-compendial impurities, metabolites and labelled analogues we hold for that drug substance.
Moxidectin9 related standardsVancomycin7 related standardsEravacycline7 related standardsMirogabalin5 related standardsFosfomycin5 related standardsTeprenone5 related standardsAzithromycin4 related standardsFolic Acid4 related standards
Three steps, no account needed
- Send the CAS number or name plus the pack size and quantity you need.
- We confirm availability — stock, lead time, documentation and shipping conditions.
- You receive a written quotation with the lot-specific COA referenced.
Enquiries reach a technical contact, not a ticket queue: chao.lu@cato-chem.com
What you get with every lot
A COA that identifies the lot
Certificates are issued per batch and reference the analytical data used to assign content or purity, so the document you file matches the vial you received.
Compounds that are genuinely hard to source
Nitrosamines, genotoxic impurities, deuterated and 13C internal standards, metabolites and toxins — the items that usually stall a method validation.
Technical guides
Written for the people who have to defend a method.
How to Choose a Reference Standard SupplierA practical checklist for evaluating reference standard suppliers on documentation, traceability, lot consistency, logistics, and technical support.Read the guide →How to Read a Certificate of Analysis (COA)A field-by-field guide to reading a certificate of analysis for reference standards, covering identity, purity, content basis, and what to query.Read the guide →Stable Isotope-Labelled Standards and When to Use ThemWhen stable isotope-labelled standards earn their place in an analytical method, what to specify when ordering, and the traps in LC-MS and GC-MS work.Read the guide →
Send us a CAS number
Availability, documentation and lead time — answered in one reply.
Storage, shipping classification and documentation questions are answered by the people who made the batch.