Methylmercury extraction from aquatic sediments - A comparison between manual, supercritical fluid and microwave-assisted techniques

During recent decades the speciation of organomercurials has been a challen ge to analytical laboratories dealing with environmental studies. Although easily detectable levels of organomercurials, and especially of methylmercu ry, are found in marine predators and biota, sediments are of fundamental i nterest as they provide a tool For assessing the impact of anthropogenic em issions on the environment. However, as in many other analytical problems, the sample-preparation stage has received less attention than the determina tion stage itself, although it is universally recognised that it determines the reliability of the analytical results. Recent developments in sample p reparation have now been applied to the methylmercury problem. In this arti cle a direct comparison is made between manual extraction, supercritical fl uid extraction and microwave-assisted extraction. Each technique was used t o extract methylmercury from polluted sediments. The efficiencies, merits a nd disadvantages of each technique are discussed. (C) 1999 Elsevier Science B.V. All rights reserved.