ASTM: D4458: Chloride in Water
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Official Method Name
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Standard Test Method for Chloride Ions in Brackish Water, Seawater, and Brines |
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Current Revision
| 1994 |
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Media
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WATER |
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Instrumentation
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Titration |
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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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This test method is based upon the Mohr procedure for determining chloride ion with silver nitrate. The chloride reacts with the silver ion before any silver chromate forms, due to the lower solubility of silver chloride. The potassium chromate indicator reacts with excess silver ion to form a red silver chromate precipitate. The end point is the appearance of the first permanent orange color. This test method is suitable for analyzing solutions with a pH between 6.0 and 8.5. |
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Scope and Application
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This test method is applicable to the measurement of chloride in highly mineralized waters such as oil field brines, seawater, and brackish water. The test method is based upon the titration of chloride with silver nitrate, using a visual indicator. |
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Applicable Concentration Range
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10 - 150 mg |
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Interferences
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Sulfide, bromide, iodide, thiocyanate, cyanide, phosphate, sulfite, carbonate, hydroxide, and iron interfere in this test method. Sulfide, sulfite, and thiosulfate can be removed with a peroxide treatment, but usually no attempt is made to remove bromide and iodide because they are usually present in insignificant quantities compared to chloride. If necessary, the pH can be raised and the hydroxides of several metals, including iron, can be filtered off. Iron, barium, lead, and bismuth precipitate with the chromate indicator. |
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Quality Control Requirements
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Sample Handling
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Collect the sample in accordance with Practices D 3370. |
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Maximum Holding Time
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Relative Cost
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Unknown |
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Sample Preparation Methods
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