EPA-ORD / EPA-OST: 200.2: Sample preparation procedure for spectrochemical determination of total recoverable elements
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Official Method Name
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Sample preparation procedure for spectrochemical determination of total recoverable elements |
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Current Revision
| Rev. 2.8, 1994, EMMC Version |
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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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Martin, T.D., Creed, J.T., and Brockhoff, C.A., 1994, Sample preparation procedure for spectrochemcial determination of total recoverable elements: U.S. Environmental Protection Agency Report, Revision 2.8, EMMC Version, 12 p. |
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Brief Method Summary
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Solid and aqueous samples are prepared in a similar manner for analysis. Nitric and hydrochloric acids are dispensed into a beaker containing an accurately weighed or measured, well mixed, homogeneous aqueous or solid sample. Aqueous samples are first reduced in volume by gentle heating. Then, metals and toxic elements are extracted from either solid samples or the undissolved portion of aqueous samples by covering the beaker with a watch glass and refluxing the sample in the dilute acid mixture for 30 minutes. After extraction, the solubilzed analytes are diluted to specified volumes with ASTM Type I water, mixed and either centrifuged or allowed to settle overnight before analysis. Diluted samples are to be analyzed by the appropriate mass and/or atomic spectrometry methods as soon as possible after preparation. |
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Scope and Application
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This method provides sample preparation procedures for the determination of total recoverable analytes in groundwaters, surface waters, drinking waters, wastewaters, and, with the exception of silica, in solid type samples such as sediments, sludges and soils. |
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Applicable Concentration Range
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Dependent on analytical method used. |
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Interferences
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In sample preparation, contamination is of prime concern. The work area, including bench top and fume hood, should be periodically cleaned in order to eliminate environmental contamination. Chemical interferences are matrix dependent and cannot be documented previous to analysis. Boron and silica from the glassware will grow into the sample solution during and following sample processing. For critical determinations of boron and silica, only quartz and/or PTFE plastic labware should be used. When quartz beakers are not available for extraction of solid samples, to reduce boron contamination, immediately transfer an aliquot of the diluted extract to a plastic centrifuge tube for storage until time of analysis. A series of laboratory reagent blanks can be used to monitor and indicate the contamination effect. |
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Quality Control Requirements
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Each laboratory determining total recoverable elements is required to operate a formal quality control (QC) program. The minimum requirements of a QC program consist of an initial demonstration of laboratory capability, and the analysis of laboratory reagent blanks, fortified blanks and quality control samples as a continuing check on performance. The laboratory is required to maintain performance records that define the quality of data generated. Specific instructions on accomplishing the described aspects of the QC program are discussed in the analytical methods used. |
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Sample Handling
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For determination of total recoverable elements in aqueous samples, the samples must be acid preserved prior to aliquoting for either sample processing or determination by direct spectrochemical analysis. For proper preservation samples are not filtered, but acidified with (1+1) nitric acid to pH <2. Preservation may be done at the time of sample collection; however, to avoid the hazards of strong acids in the field, transport restrictions, and possible contamination it is recommended that the samples be returned to the laboratory within two weeks of collection and acid preserved upon receipt in the laboratory. Following acidification, the sample should be mixed and held for 16 hours. (Normally, 3 mL of (1+1) nitric acid per liter of sample is sufficient for most ambient and drinking water samples). The pH of all aqueous samples must be tested immediately prior to withdrawing an aliquot for processing to ensure the sample has been properly preserved. If for some reason (such as high alkalinity) the sample pH is verified to be >2, more acid must be added and the sample held for 16 hours until verified to be pH <2. If properly acid preserved, the sample can be held up to six months before analysis. Note: When the nature of the sample is either unknown or is known to be hazardous, acidification should be done in a fume hood. Solid samples require no preservation prior to analysis other than storage at 4oC. There is no established holding time limitation for solid samples. For aqueous samples, a field blank should be prepared and analyzed as required by the data user. Use the same container and acid as used in sample collection. |
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Maximum Holding Time
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2 weeks |
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Relative Cost
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Unknown |
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Sample Preparation Methods
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