Unlocking the Advantages of Combining Evaporative Light-Scattering and UV Detection in Flash Chromatography

Evaporative Light-Scattering Detection, or ELSD, is utilized in flash chromatography to identify non-UV absorbing compounds. The ELSD is typically an optional accessory integrated with the flash system by the manufacturer, but in some cases, it is a modular solution that can be added to the flash chromatography system later.
Carbohydrates, lipids, and polymers are typically thought of as the main application areas for ELSD. Yet, many small molecules can be detected more efficiently with the help of ELSD, even if they are UV absorbent. Sometimes, their UV absorption is masked by the purification solvents, such as ethyl acetate, acetone, and toluene and ELS detectors can help to detect these molecules.
One of the most popular flash chromatography solvents is ethyl acetate (EtOAc), which is typically used with either hexane or heptane. While hexane and heptane are UV transparent, EtOAc is not and absorbs UV light between 200 and 252 nm with a UV maximum of 220 nm.