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Agilent Preparative LC Scaling Calculator

Agilent InfinityLab preparative LC columns

This calculator can help you:

  • Scale analytical method parameters to your preparative column. Calculate key method parameters (like flow rate, injection volume, or gradient) for your preparative column. The calculator also accounts for differences in particle size, column lengths and system dwell volumes to ensure seamless scale up.
  • Scale preparative method conditions to your analytical column. Calculate analytical method conditions based on an established preparative method. This can be helpful when investigating analytical columns with alternate dimensions and particle sizes to improve screening throughput.
  • Calculate column capacity and total number of injections. Use the column capacity and injection number to determine the perfect size preparative column for your purification campaign.
  • Calculate time and mobile phase consumption. Use these values to manage solvent inventory and instrumentation scheduling.

Using the prep scaling calculator is simple

  • Use the “Switch method” button to set the scaling direction (i.e., analytical to preparative versus preparative to analytical).
  • Enter the required fields (indicated by *) to calculate your scaled method.
  • Click on the
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  • Input
  • Output
  • Required field

Note: Preparative to analytical scaling calculations do not take dwell volume into consideration.

Switch method
  Analytical Method Preparative Method
System Description
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Name of each chromatographic instrument (e.g., “1260 Infinity II Preparative LC” or “1260 Infinity II Analytical LC”)

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Minimum instrument flow rate

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Maximum instrument flow rate

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Volume from the mobile phase mixing point to the column inlet. Learn more

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Time required for the autosampler to complete one injection cycle

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Solvent name (e.g., “Water + 0.1% formic acid”)

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Solvent name (e.g., “Acetonitrile + 0.1% formic acid”)

Column Information
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Stationary phase name (e.g., “ZORBAX SB-C18”).

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Column particle size

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Column internal diameter

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Column length

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Method flow rate

    This value exceeds the maximum flow rate. The gradient table will be calculated using the maximum flow rate.
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Method injection volume

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Estimated concentration of the target compound in the sample

Override preparative flow rate
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Select “yes” to scale the analytical gradient program to a user-defined preparative flow rate; select “no” to use the preparative flow rate scaled from the analytical flow rate

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Total mass of purified target compound

Current mass on column (mg)
Estimated column capacity (mg)
Column void volume (mL)
Analytical Gradient Preparative Gradient
Time (min) Flow (mL/min) %A %B Time (min) Flow (mL/min) %A %B

Helpful information

Mobile Phase Use Per Gradient A B Total
Analytical method (mL)
Preparative method (mL)
Number of injections
Total purification time (min)

Dwell volumes for common systems

Analytical systems

  • 1260 Infinity II LC: 0.95 mL
  • 1260 Infinity II Prime LC: 0.58 mL

Preparative system

  • 1260 Infinity II Preparative LC: 6.4 mL

Determine the dwell volume

Use the following step gradient method to determine the dwell volume of a chromatographic system.

  1. Prepare solvent A: 100 % water
  2. Prepare solvent B: 99 % acetonitrile and 1 % acetone
  3. Replace the column by a restriction capillary 0.005" id (0.12 mm id) × 750 mm.
  4. Set the detection wavelength to 263 nm.
  5. Run a step gradient at 4 minutes from 10 to 90 % B at a flow rate of 2 mL/min.
  6. Note that when using sample loops with volumes larger than 5 mL, the flow rate needs to be increased. A good compromise is to keep the flow rate equal to the loop size.

  7. Calculate the time difference (tdwell) between the programmed gradient and the obtained signal curve at 50 %.
  8. vdwell can be calculated from vdwell = tdwell × f

Questions? Our preparative LC team is here to help.

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