EPA-NERL: 100.2: Asbestos in Water by TEM
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Official Method Name
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Determination of Asbestos Structures Over 10 um in Length in Drinking Water |
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Current Revision
| June 1994 |
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Media
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WATER |
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Instrumentation
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Transmission Electron Microscopy |
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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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Known aliquots of a sample are filtered through a 0.1 to 0.22 um pore mixed cellulose ester (MCE). A carbon extraction replica is prepared from a portion of the filter and is examined in the TEM at a magnification of 10,000 to 20,000X. Asbestos structures are identified by morphology, selected area electron diffraction (SAED) and energy dispersive x-ray analysis (EDXA). Structures are then classified. |
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Scope and Application
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This method determines the presence and quantitation of asbestos structures in drinking water samples. This method allows for the quantitation of structures greater than 10 um in length. |
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Applicable Concentration Range
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See method. |
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Interferences
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The following minerals exhibit morphological, chemical or crystal structure similarities similar to the asbestos minerals: Antigorite, Attapulgite (Palygorskite), Halloysite, Horneblende, Pyroxenes, Sepiolite, Vermiculite scrolls. |
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Quality Control Requirements
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The quality control checks generally follow those specified in the Federal Register for AHERA analysis of air samples, and the NISTIR document relating to airborne asbestos analysis. Requirements are specified in the method, and include: sample receiving checks, sample prep checks (supplies and reagents, grid opening size, clean air monitoring, lab blank, etcher blank, grids/sample), sample analysis checks(system check, alignment check, mag calibration, camera constant, EDS line), performance checks (lab blanks, replicates, duplicates, standards, SRM, data entry, SAED patterns), and calculation checks. |
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Sample Handling
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Extensive sample handling requirements are specified in the method, and include: bottle prep, steps to avoid contamination, sample shipment, sample preservation, and sample compositing. |
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Maximum Holding Time
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Filter within 48 hours of collection. |
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Relative Cost
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$51 to $200 |
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Sample Preparation Methods
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