LC Solvents and Spectral Considerations with a New Process Liquid Chromatographic Optical Absorbance Detector

A selectable multiwavelength optical absorbance detector with a dual flow-through cell has been developed for use in process LC. Discreet UV wavelengths from 214 nm to 350 nm, as well as longer wavelengths into the visible region, are available. Continuous process monitoring and control places stringent constraints upon the process detector. In many cases, it requires a compromise between solute detectability and the use of solvents and conditions that provide both the separation and the long-term stability necessary for process control. Operation of the optical absorbance detector with low pressure discharge sources at wavelengths of 214 nm, 229 nm, and 254 nm is described with many of the common LC solvents. In addition, solvent spectral scans and the effect of dissolved oxygen on the UV scans are presented.