1992 Volume 8 Issue 1 Pages 35-39
A method has been proposed for the differential determination of mercury compounds in sediments, based on their successive extraction followed by a cold vapor atomic absorption spectrometric (CVAAS) determination. Organic mercury was first extracted by shaking a sediment sample with chloroform. The mercury in the extract was subsequently back-extracted into a 0.01M sodium thiosulfate solution. In order to separate mercury(II) oxide from mercury(II) sulfide, the residue was treated with 0.05M sulfuric acid so as to extract only mercury(II) oxide. Mercury(II) sulfide was finally extracted from the residue with 1M hydrochloric acid containing 3% sodium chloride in the presence of copper(I) chloride. The mercury in each extract was determined by CVAAS. When artificial standard sediment samples spiked with a given amount of each mercury compound were successively treated by the above-mentioned procedures, the recoveries of organic mercury, mercury(II) oxide and mercury(II) sulfide were 99.9, 99.5 and 98.2%, respectively. This method was successfully applied to a differential determination of mercury compounds in marine sediments.
