Imre Molnár will lecture at Eastern Analytical Symposium in Somerset, New Jersey, on the modelling of HPLC method robustness.

Tolerance limits are crucial parameters in U(H)PLC method modelling if a method should yield decent separations, even if influential factors change at the same time.

To keep the U(H)PLC method functional we have to look at all the possible changes carefully. This is done with DryLab 4 Modelling software, where we can test three levels of six factors, i.e. 3^6 =729 different variants of chromatograms in less than 30 seconds.

We can see the distribution of the critical resolution values, and have for each case a real chromatogram with a precision of MT 99% accuracy.

We can also test which factor has the strongest influence on results and change tolerance limits and the position of the working point to be able to keep out of specification (OoS) data to a minimum. We can optimise in this way the success in routine QC work and save several weeks of multifactorial robustness work.