Chromatography Forum

Hi All,

I am working on a normal phase HPLC method from last 1 month. Now my HPLC is due for calibration.I have to now prepare my system for reverse phase for calibration purpose & then again convert it back to normal phase. Can anybody help me know is there any suitable method of calibrating HPLC system using normal phase mobile phase? Is it correct to use a system continuously in normal phase which has been calibrated using reverse phase methods?

thanks,
Vaishali

My opinion, and I'm not a cGMP expert, is there's no need to requalify for normal phase, or when you convert back. Just run system suitability each time you use it, and document that.

If your company has an SOP that says you must requalify each time you change, and you do cGMP or GLP, then you must, or revise that SOP.

Many companies seem to get their underwear tied up in knots over their own over-stict paranoias.