Standard Methods: 4110D: Anions in Water by Ion Chromatography
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Official Method Name
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Test Method D. Ion Chromatographic Determination of Oxyhalides and Bromide |
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Current Revision
| Standard Methods Online |
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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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Brief Method Summary
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A water sample is injected into a stream of eluent and passed through a series of ion exchangers. Anions are separated on the basis of their relative affinities for a low-capacity, strongly basic anion exchanger. Anions are directed through a suppressor device that provides continuous suppression of eluent conductivity and enhances analyte response. In the suppressor the separated anions are converted to their highly conductive acids forms while the conductivity of the eluent is greatly decreased. The separated anions in the acid forms are measured by conductivity and indentified on the basis of retention time as compared to standards. |
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Scope and Application
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This method is applicable to untreated and finished drinking water as well as drinking water at various stages of treatment. |
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Applicable Concentration Range
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None given |
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Interferences
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Any ionic material that coelutes with a target analyte will interfere with the determination of that analyte. Bromate has been shown to be subject to positive interferences in some matrices. Chloride or a non-target analyte present in unusually high concentration may overlap with a target analyte sufficiently to cause problems in quantitation or may cause retention-time shifts. |
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Quality Control Requirements
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Preferably check recovery daily at reporting level using a reporting-level standard. Recovery should be between 75 and 125%. Alternate analysis of mid-range and high-range check standards after each 10 samples. Recovery should be between 90 and 110%. If the results are to be used for environmental compliance monitoring, document precision and accuracy of the method by the analysis of four replicates of a mid-range calibration standard and calculation of the average percent recovery, and the standard deviation of the recoveries, for each analyte. Additional QC may be required for regulatory purposes. |
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Sample Handling
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Collect samples to be analyzed for chlorite in opaque containers and store them at 4oC. All of the oxyhalides, including chlorite, require preservation with 50 mg/L ethylenediamine (EDA). If chlorine dioxide is suspected to be present, purge sample with an inert gas such as nitrogen, helium, or argon for approximately 4 min at time of collection, before adding ethylenediamine preservative. |
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Maximum Holding Time
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None given |
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Relative Cost
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$51 to $200 |
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Sample Preparation Methods
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