Chromatography Forum

At our last PM we had a new detector installed and our sensitivity has increased. This is causing some of our analytes to get saturated where in the past they were not.

To combat this we have increased the voltages on the problem analytes to make their ionization less efficient and prevent the saturation.

Would this change require a re-validation of the method for a clinical lab?

I would be inclined to revisit the linearity and precision portions of the validation...

Yes. Of course the detector must be commission and qualified. You will have to re-write your SOP including any dilutions you add or reduced injection volumes. I agree linearity and precision should be evaluated at a minimum and maybe more.

Specificity too! Since, you will have to demonstrate sensitivity to both your API as well as its related substances (based line resolve to 0.05% of the API mass as required by ICH Q3).