Abstract
To examine a simplified and rapid determination method for mercury in sediment, three digestion procedures (included official testing method for sediment and two open system methods) were investigated. The recommended procedure was as follows : A 1Og of air-dried sediment is digested with HNO3/H2SO4/KMnO4/K2S2O8 in Erlenmeyer flask at 100°C for 2h, then the mercury is determined by cold vapour AAS.
Recovery of mercury, added as Hg2+, methyl-and ethyl-mercury chloride and phenylmercury acetate to a river sediment, ranged from 100104%. Analytical results of Pond Sediment (NIES certified reference material) and 13 sediments were well agreed with reference value or results of official method (digestion with HNO3/KMnO4 in flask with reflex condenser).
The coefficient of variation was 1.0% for the reference material and ground river sediment. In the case of digestion with HNO3/NaCl in Kjeldhal flask at 100°C for 2h, recovery of mercury was 100% for the various mercury compounds added to a sediment except methylmercury chloride whose recovery was 80%. This procedure was interfered from residual volatile organics in digested solution.
