Most tools that call themselves an HPLC simulator redraw a stored picture when you move a slider. PureAnalyt does not store chromatograms. Every peak you see is computed from the same equations that describe a real column, which is why the trade-offs behave the way they do on a bench instrument: push the flow rate up and you gain time but lose plates and pay in pressure, exactly as the physics requires.
Here is what is under each control:
| What you change | What the solver applies | What you observe |
|---|---|---|
| Flow rate, particle size, column length | Van Deemter equation for plate height | Efficiency (N) peaks at an optimum velocity, then degrades |
| Flow rate, viscosity, particle size | Darcy law, pressure scales with 1/dp² | Realistic backpressure, and a real pressure limit you can exceed |
| Organic modifier (% B) | Snyder linear solvent strength model | log k falls linearly with % B, at a slope set by the analyte |
| Gradient slope and hold | LSS gradient theory with the analyte S parameter | Band compression and the elution order changes that come with it |
| Column oven temperature | Van ’t Hoff relationship | Retention drops and selectivity shifts, not uniformly across analytes |
| Mobile-phase pH | Henderson-Hasselbalch on each analyte pKa | Ionisable compounds move; neutrals do not |
| Column chemistry | Snyder-Dolan hydrophobic subtraction model (H, S*, A, B, C) | Genuine selectivity differences between C18 columns |
| Detector choice | Response model per detector, including exact-mass MS | UV-DAD, FLD, RID, ELSD, CAD and LC-MS/MS behave differently on the same sample |
What you can simulate
- Isocratic and gradient elution, including multi-step gradients, with the band compression that gradients actually produce.
- Reversed phase, normal phase, HILIC, ion exchange and size exclusion, with SEC reporting Mn, Mw and polydispersity.
- Eight detectors: UV-DAD, fluorescence, refractive index, ELSD, CAD, conductivity, and single-quadrupole and triple-quadrupole MS with ESI+, ESI- and APCI ionisation in full-scan, SIM and MRM.
- Method robustness through a resolution map that sweeps two variables at once and colours the critical pair resolution across the whole design space.
- Instrument faults: leaks, air bubbles, a fouled column, a failing lamp, a badly prepared mobile phase, sample overload and a cold oven, each with its own signature in the chromatogram.
Who this is built for
Method development chemists use it to narrow the experimental space before booking instrument time, so the injections they do run are the ones worth running. QC laboratories use it to explore how far a validated method can drift before it fails system suitability, which is the practical content of a robustness study. Educators use it because a student can destroy a separation twenty times in an afternoon and learn from every one of them, at zero cost in solvent, columns or instrument time. Students and trainees use it to connect the equations in the textbook to the shape of a peak.
Aligned with how regulators expect methods to be developed
The workflow follows the enhanced approach described in ICH Q14 and the quality by design principles of ICH Q8. You declare an Analytical Target Profile up front, stating the resolution, efficiency, tailing, precision, run time and pressure your method must deliver. The resolution map then identifies the Method Operable Design Region, the block of conditions where every one of those criteria holds at once, rather than the single point where resolution happens to peak. Reporting a region instead of a point is the difference between a method that survives daily use and one that only worked on the day it was developed.
To be precise about a claim that is often overstated: software does not make a laboratory compliant. What the simulator does is let you develop and document a method the way these guidelines expect, and produce the evidence for the design region you chose.