In a 500 mL beaker, a 20 ppm solution of HgCl2 (200 mL) was added along with silica gel coated with poly(S-r-limonene) (4.00 g). The sorbent was prepared as described above and contains a 10:1 mass ratio of silica to the poly(S-r-limonene) coating. The mixture was stirred for 10 minutes and then the sorbent was isolated by filtration and dried under vacuum before splitting up into 500 mg portions. The sorbent samples, bound to mercury, were then added to 50 mL centrifuge tubes, followed by 50 mL of solutions of varying pH or sodium chloride concentrations (pH of 3, 5, 7, 9, 11, or aqueous solutions of 6.85 mM or 599 mM NaCl, prepared as described in the sorption experiments). The mixtures were rotated on an end-over-end mixer and sampled at 10 minutes, 3 hours, and then 1, 2, 8, 14, 21, and 28 days. All samples were diluted 10-fold with 5% HCl and then mercury concentrations were determined by CVAAS.