EPA-RCA: 3520C: Continuous Liquid-Liquid Extraction of Organics
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Official Method Name
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EPA Method 3520C, Continuous Liquid-Liquid Extraction |
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Current Revision
| Revision 3, December 1996 |
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Media
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WATER |
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Instrumentation
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Continuous Liquid-Liquid Extractor |
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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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A measured volume of sample, usually 1L, is placed into a continuous liquid-liquid extractor, adjusted, if necessary, to a specific pH, and extracted with organic solvent for 18-24h. The extract is dried, concentrated (if necessary), and, as necessary, exchanged into a solvent compatible with a cleanup or determinative method being employed. |
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Scope and Application
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This method describes a procedure for isolating organic compounds from aqueous samples. The method also describes concentration techniques suitable for preparing the extract for the appropriate determinative steps. This method is applicable to the isolation and concentration of water-insoluble and slightly soluble organics in preparation for a variety of chromatographic procedures. |
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Applicable Concentration Range
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None specified. |
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Interferences
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The decomposition of some analytes has been demonstrated under basic extraction conditions required to separate analytes. Organochlorine pesticides may dechlorinate, phthalate esters may exchange, and phenols may react to form tannates. These reactions increase with increasing pH, and are decreased by the shorter reaction times available in Method 3510. |
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Quality Control Requirements
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Any reagent blanks, matrix spikes, or replicate samples should be subjected to exactly the same analytical procedures as those used on actual samples. Refer to Chapter One for specific quality control procedures and Method 3500 for extraction and sample preparation procedures. |
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Sample Handling
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See the introductory material to this chapter, Organic Analytes, Sec 4.1, SW-846 |
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Maximum Holding Time
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See introductory material, Organic analytes, Sec. 4.1. |
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Relative Cost
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Unknown |
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Sample Preparation Methods
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See intro. material, Sec 4.1, SW-846. |
