EPA-ORD / EPA-OST: 554: Carbonyl Compounds in Drinking Water by HPLC
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Official Method Name
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Method 554: Determination of Carbonyl Compounds in Drinking Water by Dinitrophenylhydrazine Derivatization and High Performance Liquid Chromatography |
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Current Revision
| Revision 1.0, August 1992 |
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Media
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WATER |
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Instrumentation
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High Performance Liquid Chromatography |
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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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A measured volume of aqueous sample, approximately 100 mL, is buffered to pH 3 and the analytes are derivatized at 40oC for one hour with 2,4-dinitrophenylhydrazine (DNPH). The derivatives are extracted from the water by passing the sample through a series of three cartridges each of which contains 500 mg of a chemically bonded C18 organic phase (liquid-solid extraction, LSE). The solid sorbent cartridges are then eluted with 10 mL of ethanol. LSE disks may also be used as long as all the (QC) criteria specified in Section 9.0 of this method are met. Liquid chromatographic conditions are described which permit the separation and measurement of the carbonyl compounds in the extract by absorbance detection at 360 nm. |
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Scope and Application
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This is a high performance liquid chromatographic (HPLC) method optimized for the determination of selected carbonyl compounds in finished drinking water and raw source water. The analytes applicable to this method are partitioned from the water onto a reverse phase C18 bonded silica packed cartridge, then eluted with ethanol. Liquid-solid extraction disks may also be used for this purpose. |
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Applicable Concentration Range
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3.0-69.0 |
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Interferences
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Glassware must be scrupulously cleaned as soon as possible after use by rinsing with the last solvent used. This should be followed by detergent washing with hot water, and rinses with tap water and distilled water. Glassware should then be drained, dried, and heated in a laboratory oven at 130oC for several hours before use. Solvent rinses with methanol may be substituted for the oven heating. The use of high purity reagents and solvents helps to minimize interference problems. |
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Quality Control Requirements
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Samples must be derivatized and extracted within 3 days of sample collection. In reagent water, the analyte concentrations remained constant over a seven-day period. In ground water, hexanal, octanal and decanal experienced losses after the first day. The other analytes degraded after the third day. |
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Sample Handling
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All samples should be iced or refrigerated at 4oC from the time of collection until extraction. |
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Maximum Holding Time
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Within 3 days, preferably 1 day. |
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Relative Cost
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Unknown |
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Sample Preparation Methods
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When sampling from a water tap, open the tap and allow the system to flush until the water temperature has stabilized (usually about two to five minutes). Adjust the flow to about 500 mL/min and collect samples from the flowing stream. Residual chlorine should be reduced at the sampling site by addition of a reducing agent (Section 7.17.4). |
