Standard Methods: 4500-CN- B: Cyanide: Preliminary Treatment of samples
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Official Method Name
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4500-CN- B. Preliminary Treatment of Samples |
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Current Revision
| Standard Methods 21st Edition (2005); Standard Methods Online |
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Media
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WATER |
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Instrumentation
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Not Applicable |
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Method Subcategory
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Sampling/Preparation |
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Method Source
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Citation
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Brief Method Summary
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The nature of the preliminary treatment will vary according to the interfering substance present. Sulfides, fatty acids, oxidizing agents, nitrites, and nitrates are removed by pre-treatment procedures. Most other interfering substances are removed by distillation. |
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Scope and Application
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This procedure is used for waters and wastewaters to eliminate interferences and distill cyanide out of solutions for determination. |
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Applicable Concentration Range
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Interferences
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Common interferences in the determination of cyanide include oxidizing agents, sulfide, fatty acids, carbonate, aldehydes, nintrite, some sulfur compounds, and substances that might contribute color or turbidity. The procedure here helps to eliminate interferences by the use of reagents for pretreatment or distillation. |
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Quality Control Requirements
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Use protocols specified in Section 4020 Quality Assurance/Quality Control to verify performance. These include daily use of reagent blanks, laboratory-fortified blanks, and known additions. Analyses for regulatory purposes may require additional quality control measures. |
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Sample Handling
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Plastic or glass containers. Add NaOH to pH >12, refrigerate in the dark. |
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Maximum Holding Time
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14 days; 24 hours if sulfide present |
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Relative Cost
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Less than $50 |
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Sample Preparation Methods
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