Single largest individual impurity

I have six replicate samples. My first three trial has largest impurity at different retention time compared to my last three samples. Let say on my first three trial, I’m getting it at 4 minutes, whereas on my last three samples, I’m getting it at 10 minutes though it has 4 minutes impurity also but lesser compared than my 10 minutes. Am I right of saying, that what I’m just going to consider on my calculation are those largest impurity coming regardless of what retention time they have? thanks.