USGS-NWQL: I-6463-86: Mercury, Total-in-Sediment, Atomic Absorption, Spectrophotometry, Flameless, Direct
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Official Method Name
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Mercury, Total-in-Sediment, Atomic Absorption Spectrophotometry, Flameless, Direct |
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Current Revision
| 1993 |
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Media
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SOILS/SEDIMENT |
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Instrumentation
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Cold Vapor Atomic Absorption |
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Method Subcategory
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Inorganic |
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Method Source
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Citation
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M.J. Fishman, 1993, Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory--Determination of inorganic and organic constituents in water and fluvial sediments: U.S. Geological Survey Open-File Report 93-125 |
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Brief Method Summary
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A sample is dried, ground, and homogenized and then is digested by a hot Lefort aqua regia solution (3:1 nitric acid to hydrochloric acid). The solution is preserved by the addition of potassium dichromate, and diluted to a known volume with demineralized water. The solution then is made basic and the mercury is reduced to the metal with stannous chloride, purged from the solution with nitrogen, and quantified by flameless-cold vapor atomic absorption spectrophotometry. |
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Scope and Application
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This method is used to analyze samples of suspended sediment and bottom material for the determination of total concentrations of mercury in samples containing at least 0.01 ug/g and not more than 5.0 ug/g. Samples containing mercury concentrations greater than 5.0 ug/g can be analyzed after appropriate dilution; either use less sediment or dilute the sample solution. This method was implemented in April 1986. Method to analyze dried and ground samples that have been digested with a combination of concentrated nitric and hydrochloric acids (Lefort aqua regia) and heat. These solutions then are analyzed by atomic absorption spectrophotometry. |
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Applicable Concentration Range
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0.01 - 5.0 (undiluted) |
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Interferences
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Volatile organic constituents interfere; however, digestion of samples with hot Lefort aqua regia will decompose organic material if present. In an alkaline media, interferences from gold, platinum, silver, copper, selenium, and tellurium are eliminated. Further information can be found in Band and Wilkinson (1972), Koirtyohann and Khalil (1976), Bartha and Ikre'nyi (1981), and Suddendorf (1981). |
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Quality Control Requirements
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Quality-control samples area analyzed at a minimum of one in every ten samples. These QC samples include at least one of each of the following: blanks, quality control samples, third party check solutions, replicates, and spikes. Correlation coefficients for calibration curves must be at least 0.99. QC samples must fall within 1.5 standard deviations of the mean value. If all of the data-acceptance criteria in the SOPs are met, then the analytical data are acceptable. |
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Sample Handling
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Description: 500 mL Polypropylene bottle, wide-mouth. Treatment and Preservation: No treatment, preservation or special shipping requirements. |
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Maximum Holding Time
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180 days from sampling |
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Relative Cost
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Unknown |
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Sample Preparation Methods
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