USGS-NWQL: I-5830-85: Postassium in Bottom Materials by Atomic Absorption Spectrometry, Total Recoverable, Bottom Material
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Official Method Name
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Potassium, Atomic Absorption Spectrometric, direct |
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Current Revision
| 1989 |
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Media
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SOILS/SEDIMENT |
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Instrumentation
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Flame 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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Potassium is determined by atomic absorption spectrometry by direct aspiration of the sample solution into an air-acetylene flame (Fishman and Downs, 1966). |
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Scope and Application
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This method may be used to analyze bottom material containing at least 10 mg/kg of potassium. Total recoverable potassium in bottom material needs to undergo preliminary digestion-solubilization before being determined. |
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Applicable Concentration Range
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>10 |
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Interferences
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Of the substances commonly occurring in water, only sodium has been found to interfere, and its interference is greatly minimized if a reducing flame is used and the burner is raised to approximately 0.05 cm below the optical light path. Alternatively, an excess of sodium or cesium may be added to all samples and standards. Such additions essentially eliminate the effects of the then comparatively minor contributions of sodium present in the samples. |
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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: 250 mL Polyethylene bottle, acid-rinsed. Treatment and Preservation: Filter through 0.45-um filter, use filtered sample to rinse containers and acidify sample with nitric acid (HNO3) to pH < 2. |
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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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Less than $50 |
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Sample Preparation Methods
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Method I-5485, TWRI Book 5, Ch. A1, p.48 |
