An evaporative light scattering detector (1) has a solvent nebuliser (4) through which an atomised spray of solute solvent solution passes, a heated evaporation chamber (5) and a detector system (6). A diffuser trapping device (7), supported by fine wires, is positioned in the evaporation chamber (5) at about two fifths of the height of the chamber from the top. The diffuser trapping device (7) is made from randomly coiled stainless steel ribbon which gives it a large surface area. The detection system (6) is positioned at the bottom of the evaporation chamber through which a beam of collimated light passes and is scattered by the solvent and detected by a light sensitive device (14). The diffuser trapping device (7) aids evaporation of the solvent and prevents large particles from travelling further down the evaporation chamber (5).