Determination of methylmercury fluxes across the air-water and air-soil interfaces by gas chromatography with electron capture detection

摘要

A method for the determination of methylmercury (MeHg) fluxes across the air-water and air-soil interfaces was developed using an in situ chamber. The MeHg in the air coming out of the chamber was captured by a column containing sulfhydryl cotton fiber adsorbent. MeHg was then desorbed from the column by using 2 mol L-1 HCl. The MeHg in the effluent was extracted with benzene, and determined by gas chromatography with electron capture detection. Finally, the MeHg flux was calculated using the chamber. The method was applied to simulated experiments, and the results showed that the MeHg fluxes in the air-water system were higher than those in the air-soil-water system. The method was also successfully applied to the field measurements of an environment polluted by a chemical factory, and the results showed that the MeHg fluxes across the air-soil and air-water interfaces were 0.21-3.09 and 0.14-0.79 ng m(-2) h(-1), respectively. The method will be a useful tool in the environmental study of MeHg.