Products

COSMOSIL C18-PREP

The large particle size C18 bulk materials are widely used for lab- to process-scale purifications. COSMOSIL offers three different particle sizes of C18 packing materials.

Particle Size, Flow Rate, and Theoretical Plate Number

Because reversed phase chromatography employs eluents of high viscosity such as methanol and water, the flow rate is lower than that of normal phase chromatography, which uses solvents of low viscosity such as hexane and ethyl acetate. In general, higher theoretical plate numbers can be obtained with lower flow rates.

Figure1

Figure 1. Concentration of methanol vs. flow rate
Column: 10 mm I.D. x 180 mm bed height (gravitational liquid flow)

Figure1

Figure 2. Flow rate vs. theoretical plate number
Column: 20 mm I.D. x 300 mm

Application Data

Separation of Vitamin E

Separation of Vitamin E
Condition
Packing material COSMOSIL 40C18-PREP
Column size 20 mm I.D. x 300 mm bed height
Mobile phase Methanol
Flow rate 9.9 ml/min
Temperature Room temperature
Detection UV 280 nm 0.2ALFS
Sample
  1. DL-α-Tocopherol (5 mg)
  2. DL-α-Tocopherol Acetate (5 mg)

Separation of Crude Drugs

Separation of Crude Drugs
Condition
Packing material COSMOSIL 40C18-PREP
Column size 20 mm I.D. x 300 mm bed height
Mobile phase Methanol:0.05% TFA = 70:30
Flow rate 9.9 ml/min
Temperature Room temperature
Detection UV 254 nm 0.05ALFS
Sample
  1. Baicalin (40 g)
  2. Baicalein (120 g)
  3. Wogonin (40 g)

Packing Material by Column Size

Column size and required amount of C18-PREP packing material

Column I.D. (mm) Bed height (mm) Column volume (ml) Amount of C18-PREP (g)
8 300 15 9
500 25 15
10 300 25 15
500 40 25
20 300 95 55
500 160 95
30 300 210 125
500 350 220
50 300 560 350
500 980 600

Packing method

Packing Method
  1. Use a standard open glass column, close the stopcock, pack a small amount of absorbent cotton in the bottom of the column and add solvent to approximately 1/3 of the column length.
  2. Add a thin layer (5 mm) of sea sand to the surface of the absorbent cotton.
  3. Prepare a slurry solution of the packing material (30% w/v) with solvent right before packing. (Make sure to prepare enough slurry solution to form a column bed sufficient to separate the compounds of interest.)
  4. Simultaneously open the stopcock and add the slurry solution to the column to form the column bed.
  5. After packing the column, wash the newly packed column bed with 5-10 column volumes of solvent. Allow the bed to stabilize overnight in solvent.
  6. Add a thin layer (5 mm) of sea sand to the top of the bed in order to prevent disturbance of the top of the column bed during sample or solvent addition.

Reference list

Ordering information

COSMOSIL C18-PREP

Product Name PKG size Product No.
COSMOSIL 50C18-PREP
Replacement for discontinued 40 µm gel
100 g 12065-84
500 g 12065-55
1 kg 12065-71
COSMOSIL 75C18-PREP
100 g 12061-24
500 g 12061-95
1 kg 12061-11
COSMOSIL 140C18-PREP
100 g 12063-04
500 g 12063-75
1 kg 12063-91

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