For many chemists, flash chromatography with UV-triggered fractionation is part of their everyday workflow. Prior to flash chromatography, the reaction mixtures are either analyzed by TLC, analyzed by LC-MS, or both to ensure the targeted product has been synthesized. But, what if the reaction created a lot of by-products? How do you find your product in a sea of impurities? In this post, I will discuss how using a flash purification system with an in-line mass detector will simplify flash purification and isolate the target molecule or molecules.