Retention time and system suitability
Posted: Sat Feb 18, 2012 11:28 pm
by pharma80
Could you please help on defining system suitability criteria regarding retention time? I am used to work upon RSD < 1% regarding 6 replicate injections, but there is no evaluation provided in the current phamacopoeias. I assume it is a rational deviation, but no theoritical information is provided.
Re: Retention time and system suitability
Posted: Sun Feb 19, 2012 2:47 am
by tom jupille
The rationale for 1% is essentially "because we can".
If you want to set a looser spec and you have the robustness data to back it up that should be OK (you may have to do some convincing of a reviewer). If you have a complex sample or close potential interfering peaks, then you might have to set your spec a bit tighter. You can't go too much tighter because many HPLC pumps only spec flow accuracy to something like 0.25%