Corona-Charged Aerosol Detection: An Analytical Approach

An alternative to other universal detection methods like refractive index (RI), low wavelength or ultraviolet (UV), and evaporative light scattering detection (ELSD), chemiluminescent nitrogen detection is a relatively new method based upon aerosol charging and involves Corona-charged aerosol detection (Corona-CAD). Some reports show that the sensitivity of this method is lower than that of fluorescence detection. Others confirm approximately five times higher sensitivity than conventional UV absorbance detection for selected analytes. This is the reason that Corona-CAD can be widely used for the determination of nonvolatile or semivolatile compounds, including: lipids, oligosaccharides, carbohydrates, proteins, steroids, surfactants, polymers, peptides, and others. The response of Corona-CAD is independent of chemical properties of the analyte. This article reviews applications of Corona-CAD and principles of the aerosol charging method as well as advantages and disadvantages of the method. The modern solution using an ultra detector, which brings charged aerosol detection to UHPLC, is also discussed.