A substance was tested for Impurity A using liquid chromatography. 2 determinations were performed.

Question

In the 1st chromatogram, Impurity A was not detected, i.e. no Impurity A peak was observed and in the 2nd chromatogram, Impurity A peak was observed with a value of 0.3%.
Is it correct to average the 2 readings to give 0.15% or should the test be repeated?

Answer 1

I don't think it is proper to average the two reading. I think the test should be repeated.