Single grain capture efficiencies n for high speed gas glow through clean granular beds are reported. The aerosol particles range in diameter Dp from about 0.6 to 4.5 um; both liquid (dioctyl phthalate) and solid (potassium biphthalate) aerosol particles were used. The grains used were spheres of diameter Dg equal to 2 or 4 mm and pen gravel with an effective diameter of 4mm. The superficial gas velocity U was varied from about 0.1 to 6 m/sec. Impaction is the dominate capture mechanism for these conditions.