EPA-NERL: 245.1: Mercury by CVAA
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Official Method Name
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Mercury (Manual Cold Vapor Technique) |
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Current Revision
| Revision 3.0, 1994 |
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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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Brief Method Summary
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A sample is digested in a glass bottle for 2 hours with a persulfate/permanganate solution under heating. After digestion, the mercury in the sample is reduced to its elemental form with stannous chloride. The concentration of mercury in the sample is determined using a cold vapor atomic absorption (CVAA) spectrometer system. |
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Scope and Application
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This method allows for determination of total mercury in drinking, surface, ground, sea, and brackish waters, and industrial and domestic wastewaters. |
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Applicable Concentration Range
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above 0.2 ug/L |
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Interferences
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(A) Ions and metals: Sulfide, chloride, copper, and tellurium are reported interferences. (B) Volatile materials: Chlorine and other volatile compounds which absorb in the range of mercury should be purged from the head space of the digestion vessel before the addition of stannous chloride. |
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Quality Control Requirements
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Quality control requirements include an initial demonstration of laboratory capability through analysis of laboratory reagent blanks (LRB), fortified blanks (LFB), quality control samples (QCS), and an MDL study. Ongoing quality control checks include analysis of laboratory fortified matrices (LFM), (laboratory reagent blanks) LRB, and instrument performance check (IPC) samples. |
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Sample Handling
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For total mercury, preserve samples with (1+1) nitric acid, and hold for 16 hours at a pH < 2 prior to analysis. Samples may be preserved in the field or upon receipt at the laboratory (the latter may minimize the chance of contamination). Use extreme care to minimize sample contamination by checking equipment, and avoiding exposure of the sample to airborne mercury in the laboratory. |
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Maximum Holding Time
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28 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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