摘要：The dithizone method for determination of mercury in JIS K 0 102 (Testing Methods for Industrial Waste Water) was improved for the determination of total mercury in sludge. In the improved method, the sludge was decomposed in HNO3-KMnO4 medium using an apparatus described in the Standard Methods for Hygienic Chemists in place of the JIS decomposition bottle. Recovery of mercury from the sludge added with C2H5HgCl was 91.2%, and was almost quantitative. Application of this method for the determinations of total mercury in sludges obtained in sea at Ichihara Industrial Area in Chiba Prefecture was proved to be fairly satisfactory. The average recovery of mercury from these sludges was 99.6%, and the deviation was within 10%.
