EPA-NERL: 110.2: Color by Spectrophotometry
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Official Method Name
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Color (Colorimetric-Platinum-Cobalt) |
|---|---|
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Current Revision
| Issued 1971 |
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Media
|
WATER |
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Instrumentation
|
Visual Comparison |
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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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Color is measured by visual comparison of the sample with platinum-cobalt standards. One unit of color is that produced by 1 mg/L platinum in the form of the chloroplatinate ion. |
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Scope and Application
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The Platinum-Cobalt method is useful for measuring color of water derived from naturally occurring materials, i.e., vegetable residues such as leaves, barks, roots, humus, and peat materials. The method is not applicable to color measurement on waters containing highly colored industrial wastes. |
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Applicable Concentration Range
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5 to 70 chloroplatinate units |
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Interferences
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(A) Turbidity: Since very slight amounts of turbidity interfere with the determination, samples showing visible turbidity should be clarified by centrifugation. (B) pH: Method is pH dependent. |
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Quality Control Requirements
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None. |
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Sample Handling
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Representative samples shall be taken in scrupulously clean glassware. Refrigerate at 4oC. |
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Maximum Holding Time
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48 hours (MCAWW, Table 1). |
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Relative Cost
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Less than $50 |
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Sample Preparation Methods
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None. |
