| Title |
Development of Gold Amalgam Voltametric Microelectrode for the Quantification of O2, Fe2+, Mn2+, and HS- |
| Authors |
권순길 ( Soongil Kwon ) ; 박동근 ( Donggeun Park ) ; 최근영 ( Geunyoung Choi ) ; 성재빈 ( Jaebin Sung ) ; 김현수 ( Hyunsoo Kim ) ; 이재우 ( Jae Woo Lee ) ; 홍용석 ( Yongseok Hong ) |
| DOI |
https://doi.org/10.15681/KSWE.2022.38.2.103 |
| Keywords |
Biogeochemistry; Heavy metals; Microelectrode; Sediment; Voltammetry |
| Abstract |
A gold amalgam voltammetric microelectrode (GAVM) system was developed for the quantification of dissolved biogeochemical species, such as O2, Fe2+, Mn2+, and HS- in sediment porewater. Commercially available Ag/AgCl and platinum electrodes were used as the reference and counter electrode, respectively, and a gold amalgam microelectrode was fabricated in the laboratory using 150-um diameter gold wire and a borosilicate capillary tube with a 1.6-mm diameter. A portable potentiostat (Metrohm, DropSens) was used for the application of voltage sweeping and to acquire the electric current. For sediment profiling, a commercially available actuator was customized and modified. The analysis method used in the system used the most widely used analysis method among the electrochemical analysis currently used The GAVM system was successively calibrated with the species and applied to estuarine sediments. The porewater analysis showed that the oxygen concentration was decreased to zero at a depth of 0.6 mm, and maximum Mn2+ and Fe2+ concentrations of 50 uM and 20 uM were detected at 2 and 3-cm depths, respectively. Maximum HS- concentrations of 10 uM were detected at 4 cm in the deeper sediments. The GAVM system was successfully developed and applied to the sediment and can be used to better understand biogeochemical reactions. |