📋 Flash Fraction Planner
Plan the number of collection tubes, time per fraction, and total run time for a flash chromatography purification.
Frequently asked questions
How do I estimate total run volume before starting?
Total run volume is typically estimated from your gradient program (in column volumes) multiplied by your column's volume, or simply from your planned total run time multiplied by flow rate. Use the Gradient Conversion Calculator or Column Volume Calculator to work out CV-based volumes first.
Why round up the number of fractions?
Rounding up (ceiling) ensures the tube count covers the entire run volume, since a partial fraction at the end still needs its own tube even if it's not completely full.
Does tube volume need to match my collector's actual tube size?
Yes — use the actual usable volume of your fraction collector's tubes or vials, which may be less than their nominal maximum capacity to avoid overflow, especially with foaming or viscous eluents.
Accuracy & how this is derived
Derivation: Simple arithmetic based on total run volume divided by fraction tube volume (rounded up) for tube count, and standard volume/flow-rate relationships for time estimates.
Validated against: Basic arithmetic — no external reference required; consistent with standard flash chromatography practice.
⚠️ For educational and research support only — verify critical results independently before use in regulated, clinical, or publication-bound work.
✔ Last updated: July 2026 · Report an error
Planning fraction collection for flash chromatography
Planning a flash chromatography purification run in advance means estimating how many collection tubes will be needed, how long each fraction takes to collect, and the total expected run time, all derived from the anticipated total elution volume, the flow rate, and the chosen fraction tube size. Knowing these numbers ahead of time helps a chemist prepare an adequately sized fraction rack and anticipate how long a purification will take before starting the instrument.