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

Riboflavin 5'-(Dihydrogen Phosphate) Monosodium Dihydrate chemical structure

Riboflavin 5'-(Dihydrogen Phosphate) Monosodium Dihydrate

CAS: 6184-17-4
Formula: C₁₇H₂₄N₄NaO₁₁P
MW: 514.4 g/mol

VQ-043554

Reference Standard

Riboflavin Impurity 3 chemical structure

Riboflavin Impurity 3

CAS: 64480-68-8
Formula: C₁₆H₂₀N₂O₇
MW: 352.34 g/mol

VQ-034660

Reference Standard

Riboflavin Tetrabutyrate chemical structure

Riboflavin Tetrabutyrate

CAS: 752-56-7
Formula: C₃₃H₄₄N₄O₁₀
MW: 656.7 g/mol

VQ-035087

Reference Standard

Riboflavin-3'-Phosphate chemical structure

Riboflavin-3'-Phosphate

CAS: 80400-93-7
Formula: C₁₇H₂₁N₄O₉P
MW: 456.3 g/mol

VQ-028728

Reference Standard

Riboflavin-4'-phosphate chemical structure

Riboflavin-4'-phosphate

CAS: 60697-29-2
Formula: C₁₇H₂₁N₄O₉P
MW: 456.3 g/mol

VQ-028729

Reference Standard

Riboflavin-4'-Phosphate Sodium chemical structure

Riboflavin-4'-Phosphate Sodium

CAS: 494789-91-2
Formula: C₁₇H₂₀N₄NaO₉P
MW: 478.3 g/mol

VQ-042921

Reference Standard

Rifabutin - Impurity D chemical structure

Rifabutin - Impurity D

CAS: 62041-01-4
Formula: C₃₇H₄₇N₃O₁₁
MW: 709.8 g/mol

VQ-027800

Reference Standard

Rifampicin Quinone chemical structure

Rifampicin Quinone

CAS: 13983-13-6
Formula: C₄₃H₅₆N₄O₁₂
MW: 820.9 g/mol

VQ-027805

Reference Standard

Rifamycin B chemical structure

CAS: 13929-35-6
Formula: C₃₉H₄₉NO₁₄
MW: 755.8 g/mol

VQ-027813

Reference Standard

Rifamycin O chemical structure

CAS: 14487-05-9
Formula: C₃₉H₄₇NO₁₄
MW: 753.8 g/mol

VQ-027816

Reference Standard

Rifamycin R chemical structure

CAS: 59264-04-9
Formula: C₃₇H₄₅NO₁₃
MW: 711.8 g/mol

VQ-041896

Reference Standard

Rifamycin S chemical structure

CAS: 13553-79-2
Formula: C₃₇H₄₅NO₁₂
MW: 695.8 g/mol

VQ-027807

Reference Standard

Rifamycin sodium salt chemical structure

Rifamycin sodium salt

CAS: 14897-39-3
Formula: C₃₇H₄₆NNaO₁₂
MW: 719.7 g/mol

VQ-027810

Reference Standard

Rifamycin Y chemical structure

CAS: 15271-73-5
Formula: C₃₉H₄₇NO₁₅
MW: 769.8 g/mol

VQ-027811

Reference Standard

Rifaximin Impurity 1 chemical structure

Rifaximin Impurity 1

CAS: 1351775-04-6
Formula: C₄₃H₄₉N₃O₁₁
MW: 783.9 g/mol

VQ-033540

Reference Standard

Rifaximin Impurity 2 chemical structure

Rifaximin Impurity 2

CAS: 1351775-03-5
Formula: C₄₃H₄₉N₃O₁₁
MW: 783.9 g/mol

VQ-027815

Reference Standard

Rilpivirine Amide Impurity 1 chemical structure

Rilpivirine Amide Impurity 1

CAS: 500288-66-4
Formula: C₂₂H₂₀N₆O
MW: 384.4 g/mol

In stock

Reference Standard

Rilpivirine Amide Impurity(N-1) chemical structure

Rilpivirine Amide Impurity(N-1)

CAS: 374067-85-3
Formula: C₁₉H₁₆BrN₅
MW: 394.3 g/mol

In stock

Reference Standard

Rilpivirine Impurity 1 chemical structure

Rilpivirine Impurity 1

CAS: 1629023-90-0
Formula: C₁₈H₁₂N₆
MW: 312.3 g/mol

VQ-027820

Reference Standard

Rilpivirine Z-Isomer chemical structure

Rilpivirine Z-Isomer

CAS: 500287-94-5
Formula: C₂₂H₁₈N₆
MW: 366.4 g/mol

In stock

Reference Standard

Riluzole 4-Trifluoromethoxy Isomer chemical structure

Riluzole 4-Trifluoromethoxy Isomer

CAS: 235101-36-7
Formula: C₈H₅F₃N₂OS
MW: 234.2 g/mol

In stock

Reference Standard

Riluzole 5-Trifluoromethoxy Isomer chemical structure

Riluzole 5-Trifluoromethoxy Isomer

CAS: 752969-85-0
Formula: C₈H₅F₃N₂OS
MW: 234.2 g/mol

In stock

Reference Standard

Riluzole Amine Dimer/Riluzole Intracyclic

Riluzole Amine Dimer/Riluzole Intracyclic

Formula: C₁₆H₁₀F₆N₄O₂S
MW: 436.33 g/mol

VQ-005775

Reference Standard

Riluzole Bromo Impurity chemical structure

Riluzole Bromo Impurity

CAS: 144631-82-3
Formula: C₈H₄BrF₃N₂OS
MW: 313.1 g/mol

In stock

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