Products

COSMOSIL 3C18-EB

Features

Column Image

  • Excellent for Basic compounds
  • Suitable for Drug Analysis

Product Information

Column Specifications

Column Specifications

Analysis of Basic Compounds

Conventionally end-capped C18 columns still have many residual silanol groups on the silica surface of stationary phase that can form ionic bonds with basic compounds. The resulting peak tailing makes accurate quantification of analytes difficult, especially in trace analyses. COSMOSIL 3C18-EB with a better end-capping treatment offers improved peak shape and separation particularly for basic compounds.

Comparison (Basic Compounds)

COSMOSIL 3C18-EB Company A
C18, 3 µm
Company B
C18, 3 µm
Company C
C18, 3 µm
Comparison_EB Comparison_A Comparison_B Comparison_C
Condition
Column Size 4.6 mm I.D. x 75 mm
Mobile Phase Acetonitrile/ 20mmol/l Phosphate
Buffer(pH7.0) = 60/40
Flow Rate 1.0 ml/min
Temperature 40°C
Detection UV 254 nm
Sample
1. Amitriptyline 
2. Propylbenzene (I.S.)
0.2mg/ml
2.0mg/ml
Amitriptyline
Inj. Vol 2.0 µl

Synthesis Reproducibility

If you use insufficiently end-capped C18 columns for basic compound analyses, you may need to spend much time adjusting mobile phase conditions. You may need

  1. more than 3 or more organic solvents or buffers
  2. ion-pair reagents or additives
  3. buffers in different pH

In addition, the complexity of the mobile phase often is detrimental to reproducibility. COSMOSIL 3C18-EB with a new end-capping treatment allows good peak shape and separation using simple mobile phase conditions.

Analysis with Simple Condition

Complicated Condition Simple Condition
Methanol/ Acetonitrile/ 20mmol/l KH2PO4, 0.2%Triethylamine(pH3.0 with H3PO4) = 35/15/50(*) Acetonitrile/ 20mmol/l Phosphate Buffer(pH2.5) = 30/70
Synthesis Reproducibility
(*): USP 38(1) Amlodipine and Benazepril Hydrochloride Capsules, Performance Tests  
Condition
Column Size 4.6 mm I.D. x 100 mm
Flow Rate 1.0 ml/min
Temperature 40°C
Detection UV 237 nm
Sample
1. Amlodipine
2. Benazepril
0.0077mg/ml
0.0225mg/ml
Inj. Vol 50 µl

Routine Analysis

3C18-EB has excellent synthesis reproducibility and column-to-column reproducibility, so it is applicable in routine analysis such as quality control of drugs.

Excellent Synthesis Reproducibility

COSMOSIL 3C18-EB
Reproducibility1
Condition
Column Size 4.6 mm I.D. x 150 mm
Mobile Phase Acetonitrile / H2O = 60/40
Flow Rate 1.0 ml/min
Temperature 40°C
Detection UV 254 nm
Sample 1. Acetophenone (0.05 mg/ml)
2. Methyl Benzoate (0.5 mg/ml)
3. Benzene (2.0 mg/ml)
4. Toluene (2.0 mg/ml)
Inj. Vol 1.5 µl
COSMOSIL 3C18-EB
Reproducibility2
Condition
Column Size 4.6 mm I.D. x 150 mm
Mobile Phase Acetonitrile/ 20mmol/l Phosphate
Buffer(pH7.0) = 60/40
Flow Rate 1.0 ml/min
Temperature 40°C
Detection UV 254 nm
Sample 1. Amitriptylin 0.2 mg/ml
2. Propylbenzene (I.S.) 2.0 mg/ml
Inj. Vol 2.0 µl

Analysis under Ammonium Acetate Buffer

COSMOSIL 3C18-EB produces sharp peaks using ammonium acetate buffer in LC-MS.

Acetonitrile/ 20mmol/l Phosphate buffer(pH7.0) = 60/40 Acetonitrile/ 10mmol/l CH3COONH4 = 60/40
LC-MS1 LC-MS2
Condition
Column Size 4.6 mm I.D. x 75 mm
Flow Rate 1.0 ml/min
Temperature 40°C
Detection UV 254 nm
Sample
1. Amitriptyline 
2. Propylbenzene (I.S.)
0.2mg/ml
2.0mg/ml
Amitriptyline
Inj. Vol 1.0 µl

Applications

Analysis of standards in USP

COSMOSIL 3C18-EB
USP_app
Condition
Column Size 4.6 mm I.D. x 100 mm
Mobile Phase A; Acetonitrile/ 36.7mmol/l Phosphate Buffer(pH7.6) = 10/90
B; Acetonitrile/ 36.7mmol/l Phosphate Buffer(pH7.6) = 80/20
B conc. 0→ 20%(0→ 10min), 20→ 100%(10→ 30min)
Flow Rate 1.0 ml/min
Temperature 40°C
Detection UV302 nm
Sample 1. Omeprazole related compound A (0.001mg/ml)
2. Omeprazole(0.001mg/ml)
Inj. Vol: 20 µl
USP 37(3) Esomeprazole Magnesium Delayed-Release Capsules, Impurities

COSMOSIL Application Search

Usage information

Column 3 µm 3C18-EB
I.D. (mm) 1.0 2.0 3.0 4.6
Washing method 1. Remove buffer, salts and/or acid from column: wash for 10-15 min. using the mobile phase last used, without buffer, salts or acid. For example, if your mobile phase was 50:50 methanol/20 mmol/l phosphate buffer, wash with 50:50 methanol/water.

2. (If you used a buffer, always do step 1 first!) Remove adsorbed compounds and fix unstable baselines by washing with methanol and/or THF.
Storage conditions Short-term (up to a week):
Remove buffer, salts and/or acid from column: wash for 10-15 min. using the mobile phase last used, without buffer, salts or acid. For example, if your mobile phase was 50:50 methanol/20 mmol/l phosphate buffer, wash with 50:50 methanol/water.

Long-term:
Remove buffer, salts and/or acid from column: wash for 10-15 min. using the mobile phase last used, without buffer, salts or acid. Then, replace the solvent with 70% methanol or acetonitrile : 30% water.

In either case, tightly plug the column, and store in a cool and dry place.
Usable pH range pH 2-10 (pH 2-7.5 recommended)
Max. pressure 30MPa
Temperature range The maximum usable temperature is 60°C. However. for regular use, please use at a constant temperature between 20°C and 50°C.
Usable solvents Any solvent that will not dissolve the silica gel (such as alkaline solutions) or cleave the stationary phase (such as very acidic solutions) is usable.
Note: For solvents with high viscosity, please watch the system pressure and keep it below 30 MPa. Also, please wash the column after using acidic mobile phases or solvents with high freezing points.
Other instructions - Buffer concentration is usually sufficient at 0.005 - 0.02 mol/L.
- Always filter mobile phases using a 0.45 µm or finer filter before use.

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Ordering Information

Product Name Size Product No. Price
COSMOSIL 3C18-EB Guard Column 4.6 mm I.D. x 10 mm 09839-41 e-Nacalai
COSMOSIL 3C18-EB
Guard Cartridge (2 PKG)** 
2.0 mm I.D. x 10 mm 11892-74 e-Nacalai
4.6 mm I.D. x 10 mm  11890-94
COSMOSIL 3C18-EB Packed Column 2.0 mm I.D. x 50 mm 09794-21 e-Nacalai
2.0 mm I.D. x 75 mm 09795-11
2.0 mm I.D. x 100 mm 09796-01
2.0 mm I.D. x 150 mm 09797-91
2.0 mm I.D. x 250 mm 09798-81
3.0 mm I.D. x 50 mm 09799-71
3.0 mm I.D. x 75 mm 09800-21
3.0 mm I.D. x 100 mm 09811-81
3.0 mm I.D. x 150 mm 09814-51
3.0 mm I.D. x 250 mm 09827-91
4.6 mm I.D. x 50 mm 09840-01
4.6 mm I.D. x 75 mm* 09841-91
4.6 mm I.D. x 100 mm* 09842-81
4.6 mm I.D. x 150 mm* 09843-71
4.6 mm I.D. x 250 mm 09844-61

* Validated Columns (available in 3 different lots)
**Cartridge Holder is required.
For more information on COSMOSIL 3.0 mm I.D. columns
Other size may be available. Please enquire.

(Storage) RT: Room temperature, A: Cool and dark, R: Refrigerator, F: Freeze