HPLC Method Transfer Calculator
Transfer an HPLC method between columns of different sizes while keeping the separation equivalent. Enter both column geometries and your original method to get the scaled flow, injection volume and gradient time.
- New injection volume
- 1.39 µL
- New gradient time
- 5.2 min
How it works
Moving an HPLC method to a column of a different size — for example to a narrower, shorter, sub-2-µm column to save solvent and time — requires scaling the method so the chromatography stays equivalent. This calculator adjusts three things geometrically. Flow rate scales with the column cross-section (internal diameter squared) and inversely with particle size to keep linear velocity constant. Injection volume scales with the column volume (diameter² × length). Gradient (or run) time scales with the column volume divided by the flow-rate change.
Enter the original and target column dimensions plus your current flow, injection and gradient time, and the equivalent values for the new column are calculated. Verify critical separations experimentally after transfer.
Examples
- Moving 4.6×150 mm, 5 µm → 2.1×50 mm, 2.6 µm lowers the flow and volumes.
- Flow scales with diameter² and inversely with particle size.
- Injection volume scales with the column volume.
Frequently asked questions
- Why scale a method between columns?
- To keep the separation equivalent. A smaller column needs proportionally less flow, injection and gradient time to reproduce the original chromatography.
- How does flow rate scale?
- With the ratio of internal diameters squared, and inversely with particle size, so the linear velocity through the packing stays constant.
- How do injection volume and gradient scale?
- Injection volume scales with column volume (diameter² × length); gradient time scales with column volume divided by the flow-rate change.
- Is the transfer exact?
- It is a geometric starting point. Differences in system dwell volume and extra-column effects mean you should verify critical separations experimentally.