Hi !!

Is there anybody knows about concentration range 4 accuracy test of impurity methods??

cheers..

We are doing it at 0.1% to 2.0% of working std. conc.

Hi
Usually we perform in 3 three levels ie 20%,60%,120% of the specification level.

Normally You decide your impurity level with respect to the concentration of your sample. Once you decide the impurity level than perform accuracy test three level below or your analytical method lower detection capacity with accurate result.