Sample Weight: 0.5 g
Mercury is determined by Cold Vapor Atomic Absorption Spectrometry (CVAAS). The sample is digested using a mixture of sulfuric and nitric acids, and dilute potassium permanganate and potassium persulfate in a water bath. Excess potassium permanganate is reduced by hydroxylamine sulfate solution, then Hg(II) is reduced by a solution of Tin(II) chloride (or stannous chloride). Mercury vapor is separated and measured with a FIMS 100 Mercury Analysis System.
The reporting limit range for Mercury is 1 ppb to 100,000 ppb.
Data will be deemed acceptable if recovery of Mercury is ±20% at five times the Lower Limit of Determination (LOD) and the calculated Relative Standard Deviation (RSD) of duplicate samples is no greater than 20%.
Central Mineral and Environmental Resources Science Center