USGS-NWQL: I-2880: Vanadium, dissolved, colorimetry
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Official Method Name
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Vanadium, colorimetry, catalytic oxidation, automated-segmented flow |
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Current Revision
| Aug-90 |
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Media
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WATER |
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Instrumentation
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Spectroscopy (Colorimetry; Photometry) |
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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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M.J. Fishman, 1993, Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory--Determination of inorganic and organic constituents in water and fluvial sediments: U.S. Geological Survey Open-File Report 93-125 |
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Brief Method Summary
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Small concentrations of vanadium catalyze the acid-persulfate oxidation of gallic acid. This reaction proceeds rapidly in the presence of vanadium but only slowly in its absence. The amount of colored oxidation product formed by this reaction is directly proportional to the concentration of vanadium when temperature, reaction time, and concentration of reactants are carefully controlled (Jarabin and Szarvas, 1961; Fishman and Skougstad, 1964; Weigo, 1983). |
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Scope and Application
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This method is used to analyze samples of most water containing from 1.0 to 40 ug/L vanadium, provided that the interferences identified below are not exceeded. Concentrations of vanadium greater than 40 ug/L must be reduced by dilution. This modified method was implemented in the National Water Quality Laboratory in August 1990. |
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Applicable Concentration Range
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1.0 to 40 ug/L |
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Interferences
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Chloride, bromide, and iodide interfere when their concentrations exceed 200 mg/L (chloride), 250 ug/L (bromide), and 250 ug/L (iodide). Iron (II), iron (III), and copper (II) interfere when their concentrations exceed 300 ug/L [iron (II)], 500 ug/L [iron (III)], and 50 ug/L [copper (II)]. The concentrations of other ions are rarely large enough to interfere. Results are erratic for samples preserved with nitric acid. |
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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 or 500 mL polyethylene bottle. Treatment and handling: Filter through 0.45-um filter; use filtered sample to rinse container. |
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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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