Skip to content

Impurities & Reference Standards

API Impurities

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

14,252products

1,516in stock

COA + SDSwith every lot

Reference Standard

Cefaclor - Impurity C chemical structure

Cefaclor - Impurity C

CAS: 143059-69-2
Formula: C₁₅H₁₄ClN₃O₄S
MW: 367.8 g/mol

VQ-022050

Reference Standard

Cefaclor Dimer chemical structure

CAS: 142975-51-7
Formula: C₃₀H₂₆Cl₂N₆O₇S₂
MW: 717.6 g/mol

VQ-024829

Reference Standard

Cefadroxil Dimer chemical structure

Cefadroxil Dimer

CAS: 2378158-45-1
Formula: C₃₂H₃₂N₆O₉S₂
MW: 708.8 g/mol

VQ-022054

Reference Standard

Cefadroxil ethyl homolog chemical structure

Cefadroxil ethyl homolog

CAS: 2243976-70-5
Formula: C₁₇H₁₉N₃O₅S
MW: 377.4 g/mol

VQ-022058

Reference Standard

Cefalexin Impurity 1 chemical structure

Cefalexin Impurity 1

CAS: 65870-51-1
Formula: C₁₁H₁₁N₃O₂
MW: 217.22 g/mol

VQ-036182

Reference Standard

Cefazolin Acid chemical structure

CAS: 25953-19-9
Formula: C₁₄H₁₄N₈O₄S₃
MW: 454.5 g/mol

VQ-022062

Reference Standard

Cefazolin Delta-2-Isomer chemical structure

Cefazolin Delta-2-Isomer

CAS: 55390-53-9
Formula: C₁₄H₁₄N₈O₄S₃
MW: 454.5 g/mol

VQ-024841

Reference Standard

Cefazolin Open Ring Lactone chemical structure

Cefazolin Open Ring Lactone

CAS: 1675245-01-8
Formula: C₁₁H₁₂N₆O₅S
MW: 340.32 g/mol

VQ-036190

Reference Standard

Cefazolin Thioxo Analog

Cefazolin Thioxo Analog

CAS: 1172998-54-7
Formula: C₁₄H₁₄N₈O₄S₃
MW: 454.51 g/mol

VQ-029687

Reference Standard

Cefdinir 7-Epimer chemical structure

Cefdinir 7-Epimer

CAS: 178601-89-3
Formula: C₁₄H₁₃N₅O₅S₂
MW: 395.4 g/mol

VQ-022075

Reference Standard

Cefdinir Decarboxy Open Ring Lactone chemical structure

Cefdinir Decarboxy Open Ring Lactone

CAS: 178949-04-7
Formula: C₁₃H₁₅N₅O₄S₂
MW: 369.4 g/mol

VQ-021090

Reference Standard

Cefdinir Glyoxalic Analog chemical structure

Cefdinir Glyoxalic Analog

CAS: 79350-14-4
Formula: C₁₄H₁₂N₄O₅S₂
MW: 380.4 g/mol

VQ-021089

Reference Standard

Cefdinir Isoxazole Analogue chemical structure

Cefdinir Isoxazole Analogue

CAS: 1356842-10-8
Formula: C₁₃H₁₁N₃O₆S
MW: 337.31 g/mol

VQ-022074

Reference Standard

Cefdinir Lactone chemical structure

Cefdinir Lactone

CAS: 946573-41-7
Formula: C₁₄H₁₃N₅O₅S₂
MW: 395.4 g/mol

VQ-022072

Reference Standard

Cefdinir Thiazine Analog chemical structure

Cefdinir Thiazine Analog

CAS: 178422-39-4
Formula: C₁₄H₁₅N₅O₆S₂
MW: 413.4 g/mol

VQ-021091

Reference Standard

Cefditoren Methoxy Methyl chemical structure

Cefditoren Methoxy Methyl

CAS: 2762536-15-0
Formula: C₂₇H₃₂N₆O₈S₃
MW: 664.8 g/mol

VQ-024846

Reference Standard

Cefditoren open ring dimer chemical structure

Cefditoren open ring dimer

CAS: 2410655-60-4
Formula: C₅₀H₅₆N₁₂O₁₄S₆
MW: 1241.5 g/mol

VQ-036196

Reference Standard

Cefditoren Pivoxil chemical structure

Cefditoren Pivoxil

CAS: 117467-28-4
Formula: C₂₅H₂₈N₆O₇S₃
MW: 620.7 g/mol

VQ-022076

Reference Standard

Cefditoren Pivoxil Dimer chemical structure

Cefditoren Pivoxil Dimer

CAS: 878002-85-8
Formula: C₅₁H₅₆N₁₂O₁₄S₆
MW: 1253.5 g/mol

VQ-034808

Reference Standard

Cefepime - Impurity C chemical structure

Cefepime - Impurity C

CAS: 104301-63-5
Formula: C₈H₁₀N₄O₃S
MW: 242.26 g/mol

VQ-022078

Reference Standard

Cefepime Declatam Lactone Decarboxylate chemical structure

Cefepime Declatam Lactone Decarboxylate

CAS: 130468-09-6
Formula: C₁₃H₁₅N₅O₄S₂
MW: 369.4 g/mol

VQ-022081

Reference Standard

Cefiderocol chemical structure

CAS: 1225208-94-5
Formula: C₃₀H₃₄ClN₇O₁₀S₂
MW: 752.2 g/mol

VQ-024851

Reference Standard

Cefixime Methyl Ester chemical structure

Cefixime Methyl Ester

CAS: 88621-01-6
Formula: C₁₇H₁₇N₅O₇S₂
MW: 467.5 g/mol

VQ-028818

Reference Standard

Cefixime Sulfone Impurity chemical structure

Cefixime Sulfone Impurity

CAS: 2682217-22-5
Formula: C₁₆H₁₅N₅O₉S₂
MW: 485.5 g/mol

VQ-029692

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