USGS-NWQL: O-3105: Chlorophenoxy acids, total recoverable
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Official Method Name
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Chlorophenoxy acids, total recoverable, gas chromatographic |
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Current Revision
| 1983 |
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Media
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WATER |
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Instrumentation
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Gas Chromatography with Electron Capture Detection |
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Method Subcategory
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Organic |
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Method Source
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Citation
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Methods for the Determination of Organic Substances in Water and Fluvial Sediments, Techniques of Water-Resources Investigations of the United States Geological Survey, Book 5, Chapter A3 Edited by R.L. Wershaw, M.J. Fishman, R.R Grabbe, and L.E. Lowe |
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Brief Method Summary
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Chlorophenoxy acid herbicides and their esters are extracted with either diethyl or methyl t-butyl ether from an acidified water sample. The extracted herbicides are hydrolyzed to the free acids which are converted to their methyl esters with boron trifluoride-methanol and purifiedusing adsorption chromatography. The methyl esters are determined by gas chromatography using electron capture detectors. |
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Scope and Application
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This method is suitable for the determination of chlorophenoxy acid herbicides, and their esters and salts, in water and water-suspended-sediment mixtures containing at least 0.01ug/L of the analyte. |
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Applicable Concentration Range
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0.01ug/l-0.6ug/l (undiluted) |
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Interferences
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Halogenated organic acids, and their salts and esters, may cause interference. |
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Quality Control Requirements
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Sample Handling
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Treatment and Preservation: Bottle baked at 450 deg C by laboratory. DO NOT RINSE BOTTLE. Do not fill bottle beyond shoulder, as reagents must be added to the sample at the NWQL before analyses. Chill sample and maintain at 4 deg C; ship immediately. |
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Maximum Holding Time
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Seven days from collection to extraction. |
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Relative Cost
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$201 to $400 |
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Sample Preparation Methods
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