USGS-NWQL: I-2057: Anions, dissolved, water, IONCHR
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Official Method Name
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Anions, ion-exchange chromatographic, automated. |
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Current Revision
| 1985 |
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Media
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WATER |
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Instrumentation
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Ion Chromatography |
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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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Chloride is determined sequentially with six other anions by ion-exchange chromatography. Ions are separated based on their affinity for the exchange sites of the resin. The separated anions in their acid form are measured using an electrical-conductivity cell. See method I-2057, anions, ion-exchange chromatographic, auto-mated, and method I-2058, anions, ion-exchange chromatographic, precipitation, automated. |
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Scope and Application
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This method may be used only for the determination of dissolved bromide, chloride, fluoride, nitrate, nitrite, orthophosphate, and sulfate in water. Samples are injected into an ion-chromatograph and pumped through an anion exchange column which separates the anions. Peaks are measured by a conductivity detector and converted in mg/L by the instrument software. |
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Applicable Concentration Range
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The range varies by analyte; consult the method for more information. |
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Interferences
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Because bromide and nitrate elute very closely together, they potentially interfere with each other. Bromide-to-nitrate peaks should not exceed 1:10 or 10:1 if both ions are to be quantitated. High levels of organic acids may be present in industrial and domestic wastes which may interfere with inorganic-anion analysis. Two common species, formate and acetate, elute between fluoride and chloride. Water from the sample may cause a negative peak or dip in the chromatogram when it elutes, because its conductivity is less than that of the suppressed eluent. Samples containing high concentrations of chloride or other anions may prevent resolution of closely eluting peaks. Unexpected, late-eluting peaks are a potential source of interference. |
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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). Method number: I-2057 (no chloride). |
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Sample Handling
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Container Description: 250 mL Polyethylene bottle. Treatment and Preservation: Filter through 0.45-um filter; using filtered sample to rinse containers. |
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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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