USGS-NWQL: I-7135: Cadmium, suspended-recoverable, water, FLAA
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Official Method Name
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Cadmium, atomic absorption spectrometric, direct |
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Current Revision
| Revised 1985 |
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Media
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WATER |
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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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Cadmium is determined by atomic absorption spectrometry by direct aspiration of the sample into an air-acetylene flame without preconcentration or pretreatment of the sample. |
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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 10 ug/L of cadmium. Sample solutions containing more than 250 ug/L need either to be diluted or to be read on a less expanded scale. Sample solutions containing less than 10 ug/L need to be analyzed by the atomic absorption spectrometric chelation-extraction method, providing that the interference limits discussed in that method are not exceeded. Suspended recoverable cadmium is calculated by subtracting dissolved cadmium from total recoverable cadmium. |
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Applicable Concentration Range
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10-250 ug/L |
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Interferences
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Individual concentrations of sodium (9,000 mg/L), potassium (9,000 mg/L), magnesium (4,500 mg/L), sulfate (9,000 mg/L), chloride (9,000 mg/L), nitrate (100 mg/L), iron (4 X 106 ug/L), and cobalt, nickel, copper, zinc, lead, and chromium (10,000 ug/L each) do not interfere. Greater concentrations of each constituent were not investigated. Calcium at concentrations greater than 1,000 mg/L suppresses the cadmium absorption. At 2,000 mg per liter of calcium, the suppression is approximately 19 percent. |
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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. (Reference OFR 95-443). |
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Sample Handling
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Container Description: 250 mL Polyethylene bottle, acid-rinsed. Treatment and Preservation: Use unfiltered sample to rinse bottles, then acidify collected sample with HNO3 to pH < 2. |
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Maximum Holding Time
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180 days |
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Relative Cost
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Less than $50 |
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Sample Preparation Methods
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