This application note describes a method for detecting combinatorial libraries using high performance liquid chromatography (HPLC) and low temperature ELSD. The method can detect low molecular weight degradation products in DMSO without interference from DMSO. This method is also discussed for its use in highlighting unstable compounds in the early stages of drug discovery.
The document explains that the Varian evaporative light scattering detector is universal and not dependent on optical properties, making it suitable for detecting compounds with weak or no UV chromophores. It highlights the utility of this method for identifying low molecular weight degradation products in DMSO without interference from the solvent itself.
The note details a specific application where organic compounds stored in frozen DMSO at 4 °C are analyzed to detect decomposition. By operating the Varian ELSD at 25 °C, it successfully detects impurities that would otherwise be masked by the DMSO peak or undetected by UV detection and mass spectrometry.
The recommended flow rate for the analysis is 1.0 mL/min.
The Varian ELSD should be operated at 25 °C to detect low molecular weight degradation products.
The nebulizer temperature is set to 25 °C and the evaporator temperature is set to 25 °C.