Effects of densities of brominated flame retardants on the detection response for HPLC analysis with a corona-charged aerosol detector.

Dependence of the response of a corona-charged aerosol detector (corona CAD) on the concentration and densities of brominated flame retardants and some related substrates was studied. The calibration curves of the substrates did not show linearity and the substrate with a lower density exhibited the stronger response. Regardless of the solvents (chloroform or toluene), and the injected volume of the substrate solution, the signal intensity of the substrate observed by a corona CAD was substantially proportional to 2/3 power law of concentration and proportional to (-2/3) power law of the density of the substrates. These results suggest that the responses should be proportional to the surface area of the particles generated through the drying process in corona CAD. Contrary to the former reports that the detector response of a corona CAD was independent of chemical species, it was proved that the response varies with the density of a substrate.