How to Deal with Mercury in Sediments? A Critical Review About Used Methods for the Speciation of Mercury in Sediments

Sediments serve as an indicator of the state of the environment, as they reveal, anthropogenic influences (e.g. industry) over time. The knowledge about the composition of sediments, in particular by the speciation, helps in the assessment of the environmental situation. The speciation of mercury in sediments is still being discussed and continues to pose a great challenge for analytical chemists. Despite a broad number of publications in this area, there is no gold-standard about the speciation of mercury in sediments. The reason for this is the growing interest in new, better methods for the speciation of mercury, which increases the number of publications and the uncertainty among the analysts. Therefore, the methodology of mercury speciation in sediments requires improvement and would benefit from a standardized approach. The goal of this review is to give an overview of the existing methods and to discuss the issues of methodology. Discussed parts in this review article include: (1) available reference material, (2) the methodology of extraction, (3) enrichment procedures, (4) separation and (5) detection. Graphical Abstract