An aqueous solution of 5 ppm HgCl2 (100 mL) was added to a 250 mL round bottom flask containing 500 mg of silica gel coated with poly(S-r-limonene). The sorbent was prepared as described above and contained a 10:1 mass ratio of silica to the poly(S-r-limonene) coating. The mixture was stirred and 1.00 mL samples of the solution were taken by pipette at 1, 2, 5, 10, 15, and 30 minutes. Any trace solids were removed by centrifugation, and the samples were diluted 10-fold with 5% HCl to stabilise mercury species for subsequent analysis. The experiment was repeated in triplicate. The experiment was also repeated with uncoated silica gel as a control.