USGS-NWQL: I-1866: Thallium, dissolved, graphite furnace
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Official Method Name
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Thallium, atomic absorption spectrometric, graphite furnace |
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Current Revision
| 1981 |
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Media
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WATER |
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Instrumentation
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Graphite Furnace-Atomic Absorption Spectrometer |
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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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Thallium is determined by atomic absorption spectrometry in conjunction with a graphite furnace and the method of standard additions. The sample is placed in the graphite tube and is then evaporated to dryness, charred, and atomized. The absorbance signal generated during atomization is recorded. Known concentrations of thallium are added to aliquots of the sample in the tube and the technique is repeated. The absorbances are then plotted and the concentration of thallium is determined by extrapolation. Pretreatment of the graphite tube with ammonium molybdate and addition of ammonium nitrate to the sample in the graphite tube are employed to reduce background scattering. For discussion of standard additions, see this chapter, Analytical techniques, atomic absorption spectrometry. |
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Scope and Application
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This method may be used to analyze water containing at least 1 ug/L of thallium. Samples containing more than 9 ug/L need either to be diluted or a smaller volume needs to be used for analysis. |
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Applicable Concentration Range
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1 to 9 ug/L |
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Interferences
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False peaks or recorder deflections below the baseline often occur during the atomization cycle because of heavy background scattering in this wavelength region (276.8 nm) and because of the requirement for very close alignment of the deuterium background corrector and source (electrodeless-discharge lamp). |
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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 1 for every 10 samples. |
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Sample Handling
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Container Description: 250 mL polyethylene bottle, nitric acid rinsed Treatment and handling: Filter through 0.45-um filter, use filtered sample to rinse container, acidify sample with nitric acid 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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$51 to $200 |
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Sample Preparation Methods
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