Skip to content

Impurities & Reference Standards

API Impurities

Source 1942 api impurities for research, QC and production, documented with COA and SDS.

14,098products

1,516in stock

COA + SDSwith every lot

Reference Standard

Febuxostat Impurity 23 chemical structure

Febuxostat Impurity 23

CAS: 2476465-06-0
Formula: C₁₇H₁₉NO₅S
MW: 349.4 g/mol

VQ-037212

Reference Standard

Febuxostat Isopropyl isomer chemical structure

Febuxostat Isopropyl isomer

CAS: 144060-52-6
Formula: C₁₅H₁₄N₂O₃S
MW: 302.4 g/mol

VQ-025732

Reference Standard

Febuxostat Isopropyl Isomer Ethyl Ester chemical structure

Febuxostat Isopropyl Isomer Ethyl Ester

CAS: 144060-84-4
Formula: C₁₇H₁₈N₂O₃S
MW: 330.4 g/mol

VQ-037209

Reference Standard

Febuxostat Methyl Ester chemical structure

Febuxostat Methyl Ester

CAS: 923942-34-1
Formula: C₁₇H₁₈N₂O₃S
MW: 330.4 g/mol

VQ-025739

Reference Standard

Febuxostat N-Butyl Isomer chemical structure

Febuxostat N-Butyl Isomer

CAS: 1657014-33-9
Formula: C₁₆H₁₆N₂O₃S
MW: 316.4 g/mol

VQ-025730

Reference Standard

Febuxostat sec-Butoxy Acid chemical structure

Febuxostat sec-Butoxy Acid

CAS: 1335202-59-9
Formula: C₁₆H₁₆N₂O₃S
MW: 316.4 g/mol

VQ-025731

Reference Standard

Febuxostat t-Butyl Ether Acid Impurity chemical structure

Febuxostat t-Butyl Ether Acid Impurity

CAS: 2418591-43-0
Formula: C₁₆H₁₆N₂O₃S
MW: 316.4 g/mol

VQ-030687

Reference Standard

Fedratinib Impurity 1 chemical structure

Fedratinib Impurity 1

CAS: 50609-01-3
Formula: C₁₂H₁₈N₂O
MW: 206.28 g/mol

VQ-044490

Reference Standard

Felbamate Dimer chemical structure

Felbamate Dimer

CAS: 1796927-91-7
Formula: C₂₁H₂₄N₂O₇
MW: 416.4 g/mol

VQ-025746

Reference Standard

Fenbendazole chemical structure

CAS: 43210-67-9
Formula: C₁₅H₁₃N₃O₂S
MW: 299.3 g/mol

VQ-022636

Reference Standard

Fenbendazole Sulfone chemical structure

Fenbendazole Sulfone

CAS: 54029-20-8
Formula: C₁₅H₁₃N₃O₄S
MW: 331.3 g/mol

VQ-021226

Reference Standard

Fenofibric Acid 1-Carboxyl-1-methylethyl Ester chemical structure

Fenofibric Acid 1-Carboxyl-1-methylethyl Ester

CAS: 1797121-54-0
Formula: C₂₁H₂₁ClO₆
MW: 404.8 g/mol

VQ-025758

Reference Standard

Fenofibric Acid Ethyl Ester chemical structure

Fenofibric Acid Ethyl Ester

CAS: 42019-08-9
Formula: C₁₉H₁₉ClO₄
MW: 346.8 g/mol

VQ-022637

Reference Standard

Fenofibric Acid Methyl Ester chemical structure

Fenofibric Acid Methyl Ester

CAS: 42019-07-8
Formula: C₁₈H₁₇ClO₄
MW: 332.8 g/mol

VQ-025753

Reference Standard

Fenoterol Hydrobromide Impurity B chemical structure

Fenoterol Hydrobromide Impurity B

CAS: 3371-33-3
Formula: C₁₇H₂₀BrNO₄
MW: 382.2 g/mol

VQ-025762

Reference Standard

Fenoxaprop Ethyl chemical structure

Fenoxaprop Ethyl

CAS: 66441-23-4
Formula: C₁₈H₁₆ClNO₅
MW: 361.8 g/mol

VQ-045189

Reference Standard

Fenoxaprop P-Ethyl chemical structure

Fenoxaprop P-Ethyl

CAS: 71283-80-2
Formula: C₁₈H₁₆ClNO₅
MW: 361.8 g/mol

VQ-032628

Reference Standard

Fenpipramide chemical structure

CAS: 77-01-0
Formula: C₂₁H₂₆N₂O
MW: 322.4 g/mol

VQ-030707

Reference Standard

Fenpipramide Hydrochloride chemical structure

Fenpipramide Hydrochloride

CAS: 14007-53-5
Formula: C₂₁H₂₇ClN₂O
MW: 358.9 g/mol

VQ-037234

Reference Standard

Fenpropimorph chemical structure

CAS: 67564-91-4
Formula: C₂₀H₃₃NO
MW: 303.5 g/mol

VQ-030709

Reference Standard

Fenspiride Impurity A chemical structure

Fenspiride Impurity A

CAS: 23808-42-6
Formula: C₁₄H₂₂N₂O
MW: 234.34 g/mol

VQ-037237

Reference Standard

Fenticonazole Impurity B Nitrate chemical structure

Fenticonazole Impurity B Nitrate

CAS: 80639-95-8
Formula: C₂₄H₂₁Cl₂N₃O₅S
MW: 534.4 g/mol

VQ-030713

Reference Standard

Fenticonazole Impurity C Nitrate chemical structure

Fenticonazole Impurity C Nitrate

CAS: 80676-29-5
Formula: C₂₄H₂₁Cl₂N₃O₆S
MW: 550.4 g/mol

VQ-037238

Reference Standard

Ferrous Ascorbate chemical structure

Ferrous Ascorbate

CAS: 24808-52-4
Formula: C₁₂H₁₄FeO₁₂
MW: 406.08 g/mol

VQ-037239

Need a price, a spec or a custom compound?

Send us your list — product names or CAS numbers, grade, quantity and destination. Our team replies with a formal quotation, COA and lead time.

Request a quote Contact sales