The nebulizer in an evaporative light scattering detector for HPLC disperses the mobile phase so that it can be readily evaporated in the heating chamber. The optimum design of the nebulizer is dependent on the flow rate of the eluent, which can range from the low µL/min range for nano LC to perhaps 4-5 mL/min when the speed of the analysis is a critical issue (e.g. in combinatorial chemistry).

The characteristics of the nebulizer that is installed in the detector should correspond to the flow rate of the mobile phase to be used for the analysis. If the nebulizer provides particles that are too large, it is possible that they will be swept into the drain; alternatively the solvent molecules will not be totally removed by the time the sample is swept into the detector head. Similarly, if the particles generated by the nebulizer are too small, the solid particles that are swept into the detector head will not be large enough to provide suitable sensitivity.

In most ELSD systems, a fixed nebulizer is used to cover the entire eluent flow rate range. This leads to a compromise that affects the performance. To optimize performance, SEDERE provides four different nebulizers for the SEDEX LT-ELSD systems (Models 75 and 85) which are interchangeable in a minute or two. The capillary nebulizer is used for flow rates between 2 µL/min and 80 µL/min, the HPLC Low Flow Nebulizer is used for flow rates between 20 µL/min and 1.0 mL/min, the HPLC nebulizer is used for flow rates between 0.2 mL/min and 1.3 mL/min and the CC (combinatorial chemistry) nebulizer is used for flow rates between 1.0 mL/min and 5.0 mL/min.