Scott Krepich on September 12, 2023 at 3:48 pm Hi Andrew, You are right, the best way to do this computation is to use custom columns. We do have a post on this, hopefully this is helpful for you to set up the equations! https://sciex.com/support/knowledge-base-articles/sciex-os-how-to-sum-concentration-for-isomers_en_us Log in to Reply