Simultaneous determination of total and speciated mercury in marine sediment: A combined analytical approach

University of Chemical Technology and Metallurgy, 8 Kliment Ohridski Blvd., 1756 Sofia, Bulgaria

^* Corresponding author: veronika@uctm.edu

Abstract

This study presents a combined analytical approach for determining total mercury (THg) and mercury species (CH₃Hg⁺ and Hg²⁺) in marine sediments. THg was measured using AMA-254, while speciation analysis was performed by GC-ICP-HRMS with double isotope dilution calibration approach. In the sediment sample, CH₃Hg⁺ was 0.00054 ± 0.00011 mg kg^-1 and Hg²⁺ was 0.118 ± 0.030 mg kg^-1. The sum of mercury species closely matched THg values obtained by AMA, confirming the method’s reliability with 85% recovery. The low detection limits enabled accurate quantification of mercury, even at trace levels. Combining both techniques allowed a clearer distinction between the main mercury species and improved understanding of their distribution in the sediment. This approach is reliable for accurate mercury determination and the results can contribute useful information for future environmental assessments and monitoring efforts.