USGS-NWQL: I-7462: Mercury, suspended recoverable, CVFAA
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Official Method Name
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Mercury, atomic absorption spectrometric, cold vapor, flameless |
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Current Revision
| 1985 |
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Media
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WATER |
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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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Methods for the Determination of Inorganic Substances in Water and Fluvial Sediments, Techniques of Water-Resources Investigations of the United States Geological Survey, Book 5, Chapter A1 Edited by Marvin J. Fishman and Linda C. Friedman |
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Brief Method Summary
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The cold-vapor, flameless, atomic absorption procedure is based on the absorption of radiation at 253.7 nm by mercury vapor. Organic mercury compounds, if present, are decomposed by hot (95oC) digestion with potassium permanganate and potassium persulfate in acid solution. The mercuric ions are then reduced to the elemental state with stannous chloride, and the mercury vapor is subsequently removed from solution by aeration and passed through a cell positioned in the light path of an atomic absorption spectrometer. This method is based on a procedure described by Hatch and Ott (1968). |
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Scope and Application
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This method may be used to analyze water and water-suspended sediment containing at least 0.5 ug/L of mercury. Samples containing mercury concentrations greater than 10 ug/L need to be diluted. Industrial and sewage effluent may be analyzed, as well as samples of fresh and saline water. Suspended recoverable mercury is calculated by subtracting dissolved mercury from total recoverable mercury. |
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Applicable Concentration Range
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0.5 ug/L to 10 ug/L mercury |
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Interferences
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Some samples may contain volatile organic compounds that absorb radiation at 253.7 nm and that may be swept from the solution along with the mercury vapor. These constitute a positive interference, and the possibility of their presence must not be overlooked. Selenium concentrations, either as selenate or selenite, up to 10,000 ug/L do not interfere; higher concentrations were not tested. |
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Quality Control Requirements
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Calibrate instrument using calibration standards (CAL). Quality control samples (QCS) and laboratory blanks (LB) analyzed at a minimum of I each after every 10 samples |
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Sample Handling
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Container Description: 250 mL Glass bottles, acid-rinsed. Treatment and Preservation: Filter through 0.45-um filter; use filtered sample to rinse containers and acidify collected sample with 10 mL of potassium dichromate preservative. (5 g pottassium dichromate/500 mL nitric acid). Use unfiltered sample to rinse bottle, then acidify collected sample with 10 mL of potassium dichromate preservative. (5 g pottassium dichromate/500 mL nitric acid) |
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Maximum Holding Time
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180 days |
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Relative Cost
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$51 to $200 |
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Sample Preparation Methods
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