Impurities and reference standards
- Chemicals
- 9,002
- Suppliers
- 6,275
About impurities and reference standards
Reference standards are highly characterised materials used to identify substances and measure their purity and impurities. This group covers pharmacopoeial reference standards from bodies such as the USP and the EDQM, secondary or working standards traceable to them, impurity standards and related compounds, metabolites, degradation products, nitrosamine standards, and isotope-labelled internal standards for mass spectrometry.
Read more about impurities and reference standardsShow less
Quality control labs, contract research organisations and API manufacturers buy them in milligram quantities for method development, validation and routine release testing. Because a single impurity standard can be hard to make, prices are high and availability changes often. Many suppliers synthesise impurities on request.
Look for a certificate of analysis that explains how the material was characterised, typically by NMR, mass spectrometry, HPLC purity, water and residual solvent content, with an assigned purity or potency value and its uncertainty. Producers accredited to ISO 17034 for reference material production and ISO/IEC 17025 for testing give extra confidence. Check the storage conditions and retest date, and confirm whether a secondary standard is traceable to a primary pharmacopoeial lot.
Top impurities and reference standards
Showing 1 to 48 of 9,002 chemicals, most searched and traded first.
PhosphateCAS 14265-44-2O4P-325 suppliers
Estradiol hemihydrateCAS 35380-71-3C36H50O558 suppliers
Cysteine hydrochlorideCAS 52-89-1C3H8ClNO2S94 suppliers
VancomycinCAS 1404-90-6C66H75Cl2N9O2466 suppliers
UridineCAS 58-96-8C9H12N2O6112 suppliers
AcetaldehydeCAS 75-07-0C2H4O159 suppliers
Norepinephrine hydrochloride, (A+-)-CAS 55-27-6C8H12ClNO363 suppliers
Morphine sulfate pentahydrateCAS 6211-15-0C34H50N2O15SRequest quotes
Omeprazole magnesiumCAS 95382-33-5C34H36MgN6O6S262 suppliers
CytosineCAS 71-30-7C4H5N3O125 suppliers
2-Amino-4-chloropyridineCAS 19798-80-2C5H5ClN2121 suppliers
CandesartanCAS 139481-59-7C24H20N6O3134 suppliers
7-Epi-taxolCAS 105454-04-4C47H51NO1460 suppliers
PyridineCAS 110-86-1C5H5N206 suppliers
((1S,5R)-8-Methyl-8-azabicyclo(3.2.1)octan-3-yl) (2R)-3-hydroxy-2-phenylpropanoateCAS 13269-35-7C17H23NO315 suppliers
Cholic acidCAS 81-25-4C24H40O5103 suppliers
MedroxyprogesteroneCAS 520-85-4C22H32O365 suppliers
D-GalactoseCAS 59-23-4C6H12O684 suppliers
FludarabineCAS 21679-14-1C10H12FN5O4103 suppliers
Fludeoxyglucose F-18CAS 63503-12-8C6H11FO510 suppliers
DL-GlutamineCAS 6899-04-3C5H10N2O395 suppliers
trans-StilbeneCAS 103-30-0C14H1272 suppliers
(E)-TamoxifenCAS 13002-65-8C26H29NO33 suppliers
Nicotine bitartrateCAS 6019-06-3C18H30N2O1434 suppliers
ThymineCAS 65-71-4C5H6N2O2107 suppliers
Ropivacaine hydrochlorideCAS 98717-15-8C17H27ClN2O85 suppliers
Dabigatran etexilate mesylateCAS 872728-81-9C35H45N7O8S130 suppliers
TicagrelorCAS 274693-27-5C23H28F2N6O4S165 suppliers
PurineCAS 120-73-0C5H4N486 suppliers
Tobramycin sulfateCAS 49842-07-1C36H84N10O38S536 suppliers
Ouabain octahydrateCAS 11018-89-6C29H60O2033 suppliers
PyrazineCAS 290-37-9C4H4N295 suppliers
ZiprasidoneCAS 146939-27-7C21H21ClN4OS75 suppliers
Chloroquine sulfateCAS 132-73-0C18H28ClN3O4S40 suppliers
CotinineCAS 486-56-6C10H12N2O72 suppliers
MefloquineCAS 53230-10-7C17H16F6N2O28 suppliers
IndoleCAS 120-72-9C8H7N165 suppliers
Docetaxel trihydrateCAS 148408-66-6C43H59NO1770 suppliers
7-Ethyl-10-hydroxycamptothecinCAS 86639-52-3C22H20N2O5115 suppliers
MontelukastCAS 158966-92-8C35H36ClNO3S118 suppliers
DopacCAS 102-32-9C8H8O493 suppliers
MelaninsCAS 8049-97-6C18H10N2O428 suppliers
GuanidineCAS 113-00-8CH5N345 suppliers
CyclopentadieneCAS 542-92-7C5H640 suppliers
Dabigatran etexilateCAS 211915-06-9C34H41N7O591 suppliers
Ivermectin B1aCAS 71827-03-7C48H74O1445 suppliers
ArmodafinilCAS 112111-43-0C15H15NO2S42 suppliers
Edetate calcium disodium monohydrateCAS 304695-78-1C10H14CaN2Na2O929 suppliers
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Top suppliers of impurities and reference standards
Manufacturers and traders with live products in this category. Paid members appear first.
TRC Finechems is a leading manufacturer and supplier of fine chemicals, intermediates, and APIs.
Impurities and reference standards suppliers by country
Countries with at least 5 suppliers in this category. Open one to see its manufacturers and traders.
- China2,625
- India1,305
- United States713
- Germany119
- Japan112
- United Kingdom84
- Italy65
- Spain63
- Canada55
- France43
- South Korea41
- Turkey41
- Thailand30
- Switzerland29
- Netherlands29
- Russia25
- Singapore25
- Bangladesh24
- Indonesia20
- Malaysia20
- Poland20
- South Africa20
- Australia19
- Czech Republic17
- Taiwan17
- Hong Kong16
- Iran16
- Egypt15
- Mexico15
- Vietnam15
- Pakistan14
- United Arab Emirates13
- Brazil10
- Philippines10
- Belgium9
- Hungary9
- Israel9
- Greece8
- Ireland8
- New Zealand8
New impurities and reference standards from suppliers
Products recently listed by manufacturers and traders in this category.
Latest buy requests for impurities and reference standards
Open requests from buyers. Suppliers can quote after signing in.
- 0 quotesPhosphonoacetic acid100 kg+ 2 more products To BangladeshQuarterly need 7 d ago
- 0 quotesPyrazine25 kg To BangladeshMonthly need 7 d ago
- 1 quoteTrans-Stilbene25 kg To Saudi ArabiaMonthly need 7 d ago
- 0 quotesTicagrelor10 kg+ 1 more products To ThailandMonthly need 7 d ago
- 1 quote5-Aminoimidazole-4-carboxamide50 kg+ 1 more products To IndiaMonthly need 7 d ago
- 0 quotesSodium methotrexate4 drums+ 1 more products To Thailand 8 d ago
Buyer names and contact details stay private until the buyer accepts a quote.
Guides for buyers
Practical reading on grades, documents, regulation and shipping before you buy.
- Article · QualityPharma grades explained: IP vs BP vs USP vs EP
What the Indian, British, US and European pharmacopoeias are, how their monographs differ, what multi grade claims mean and why a grade alone does not make a product fit for medicines.
- Article · SourcingHow to write an RFQ that gets fast and accurate quotes
What suppliers need to quote quickly and comparably: exact product identity, quantity and packing, delivery terms, documents, samples and payment, with a ready to use template.
- Guide · Trade and logisticsIncoterms 2020 for chemical buyers
The eleven Incoterms 2020 rules from a chemical buyer's point of view, with the traps around CIF insurance, FOB for containers, EXW exports, DDP imports and dangerous goods.
Frequently asked questions
Quick answers about buying impurities and reference standards on CompoundList.
What are impurities and reference standards?
Pharmacopoeial impurities, related compounds and reference standards used for quality control and method validation.
How many impurities and reference standards are listed on CompoundList?
CompoundList lists 9,002 chemicals in impurities and reference standards. 6,275 suppliers offer products in this category.
Which impurities and reference standards are the most popular?
The most searched and traded impurities and reference standards on CompoundList include Phosphate, Estradiol hemihydrate, Cysteine hydrochloride, Vancomycin and Uridine. They are part of the wider pharmaceuticals and APIs family.
How do I buy impurities and reference standards in bulk?
Open a chemical to compare its suppliers, or post one buy request with the product, grade, quantity and destination. Matching suppliers send you quotes, and your contact details stay private until you accept one.