All other samples had mercury levels at or below the limits of detection by CVAAS, indicating leaching was not significant for pH = 2, 5, 7, or 9. Leaching was also not significant for the samples with added sodium chloride. SEM analysis of the sorbent did reveal that the high pH degrades the polymer coating (Figs and). This could lead to the release of mercury, perhaps bound to suspended polymer particles (or the products of polymer degradation). Further study is required to determine the mechanism and speciation of the mercury leaching at elevated pH. However, minimal leaching was observed for all other samples suggesting that the mercury remains strongly bound to the sorbent even in highly acidic media or brine.