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

Cefixime tert-Butyl Ester chemical structure

Cefixime tert-Butyl Ester

CAS: 79368-92-6
Formula: C₂₀H₂₃N₅O₇S₂
MW: 509.6 g/mol

VQ-022084

Reference Standard

Cefmetazole Ditetrazole chemical structure

Cefmetazole Ditetrazole

CAS: 74228-11-8
Formula: C₁₅H₁₈N₁₀O₅S₃
MW: 514.6 g/mol

VQ-043104

Reference Standard

Cefmetazole Lactone chemical structure

Cefmetazole Lactone

CAS: 70993-70-3
Formula: C₁₃H₁₃N₃O₅S₂
MW: 355.4 g/mol

VQ-034809

Reference Standard

Cefodizime Impurity 1

Cefodizime Impurity 1

CAS: 111874-11-4
Formula: C₂₀H₂₀N₆O₇S₄
MW: 584.7 g/mol

VQ-045402

Reference Standard

Cefoperazone Acid chemical structure

Cefoperazone Acid

CAS: 62893-19-0
Formula: C₂₅H₂₇N₉O₈S₂
MW: 645.7 g/mol

VQ-024855

Reference Standard

Cefoperazone Impurity 11

Cefoperazone Impurity 11

CAS: 73240-09-2
Formula: C₂₃H₂₅N₅O₉S
MW: 547.5 g/mol

VQ-045403

Reference Standard

Cefotaxime Acid chemical structure

Cefotaxime Acid

CAS: 63527-52-6
Formula: C₁₆H₁₇N₅O₇S₂
MW: 455.5 g/mol

VQ-029696

Reference Standard

Cefotaxime Bromoacetyl Analog chemical structure

Cefotaxime Bromoacetyl Analog

CAS: 83305-12-8
Formula: C₁₅H₁₆BrN₃O₈S
MW: 478.3 g/mol

VQ-022092

Reference Standard

Cefotaxime Sodium Impurity 2

Cefotaxime Sodium Impurity 2

CAS: 126747-48-6
Formula: C₁₆H₁₇N₅O₇S₂
MW: 455.5 g/mol

VQ-045404

Reference Standard

Cefotetan Lactone chemical structure

Cefotetan Lactone

CAS: 2058102-28-4
Formula: C₁₅H₁₃N₃O₈S₃
MW: 459.5 g/mol

VQ-029698

Reference Standard

Cefovecin Dioxime chemical structure

Cefovecin Dioxime

CAS: 2916470-18-1
Formula: C₂₃H₂₄N₈O₈S₃
MW: 636.7 g/mol

VQ-024860

Reference Standard

Cefovecin R-Isomer

Cefovecin R-Isomer

CAS: 775549-10-5
Formula: C₁₇H₁₉N₅O₆S₂
MW: 453.49 g/mol

VQ-024859

Reference Standard

Cefpodoxime Proxetil Isopropylcarbamate chemical structure

Cefpodoxime Proxetil Isopropylcarbamate

CAS: 1192365-87-9
Formula: C₂₅H₃₃N₅O₁₁S₂
MW: 643.7 g/mol

VQ-024865

Reference Standard

Cefprozil (E)-Isomer Monohydrate chemical structure

Cefprozil (E)-Isomer Monohydrate

CAS: 111900-24-4
Formula: C₁₈H₂₁N₃O₆S
MW: 407.4 g/mol

VQ-029705

Reference Standard

Cefprozil (Z)-Isomer chemical structure

Cefprozil (Z)-Isomer

CAS: 121412-77-9
Formula: C₁₈H₁₉N₃O₅S
MW: 389.4 g/mol

VQ-024867

Reference Standard

Cefprozil Delta-3 Isomer chemical structure

Cefprozil Delta-3 Isomer

CAS: 1000980-59-5
Formula: C₁₈H₁₉N₃O₅S
MW: 389.4 g/mol

VQ-024845

Reference Standard

Cefprozil E-isomer chemical structure

Cefprozil E-isomer

CAS: 92676-86-3
Formula: C₁₈H₁₉N₃O₅S
MW: 389.4 g/mol

VQ-043107

Reference Standard

Cefprozil Monohydrate - Impurity F chemical structure

Cefprozil Monohydrate - Impurity F

CAS: 107937-01-9
Formula: C₁₀H₁₂N₂O₃S
MW: 240.28 g/mol

VQ-036201

Reference Standard

Cefradine chemical structure

CAS: 38821-53-3
Formula: C₁₆H₁₉N₃O₄S
MW: 349.4 g/mol

VQ-022100

Reference Standard

Cefradine Impurity 1 chemical structure

Cefradine Impurity 1

CAS: 37051-00-6
Formula: C₁₆H₂₁N₃O₄S
MW: 351.4 g/mol

VQ-029707

Reference Standard

Ceftaroline Fosamil Impurity 1 chemical structure

Ceftaroline Fosamil Impurity 1

CAS: 1277090-03-5
Formula: C₂₈H₃₄N₁₂O₁₀PS₄-
MW: 857.9 g/mol

VQ-044168

Reference Standard

Ceftaroline Fosamil Impurity 18 chemical structure

Ceftaroline Fosamil Impurity 18

CAS: 953037-68-8
Formula: C₂₂H₂₁N₈O₈PS₄
MW: 684.7 g/mol

VQ-036206

Reference Standard

Ceftaroline Fosamil Impurity 5 chemical structure

Ceftaroline Fosamil Impurity 5

CAS: 953037-71-3
Formula: C₂₂H₂₀N₈O₅S₄
MW: 604.7 g/mol

VQ-024869

Reference Standard

Ceftaroline Fosamil Impurity 6 chemical structure

Ceftaroline Fosamil Impurity 6

CAS: 1286218-68-5
Formula: C₄₄H₄₀N₁₆O₁₅P₂S₈
MW: 1351.4 g/mol

VQ-022103

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