EPA-NERL: 100.1: Asbestos in Water by TEM
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Official Method Name
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Analytical Method for Determination of Asbestos Fibers in Water |
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Current Revision
| September 1983 |
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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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A water sample is filtered through a 0.1 micrometer pore size Nuclepore polycarbonate filter. A carbon coating is then applied in vacuum to the active surface of the filter. The carbon layer coats and retains the position of the material which has been collected on the filter surface. A small portion of the carbon-coated filter is placed on an electron microscope grid and the polycarbonate filter material is removed by dissolution in an organic solvent. The carbon film containing the original particulate, supported on the electron microscope grid, is then examined in a transmission electron microscope (TEM) at a magnification of about 20,000. In the TEM, selected area electron diffraction (SAED) is used to examine the crystal structure of a fiber, and its elemental composition is determined by energy dispersive X-ray analysis (EDXA). |
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Scope and Application
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This method determines the numerical concentration of asbestos fibers, the length and width of each fiber, and the estimated mass concentration of asbestos in drinking water. Fiber size and aspect ratio distributions are also determined. The method permits, if required, identification of all mineral fibers found in water. In particular, chrysotile can be distinguished from the amphiboles, and fibers of specific amphiboles can be identified. |
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Applicable Concentration Range
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Depends on turbidity, size, and distribution of fibers. For low turbidity 0.1 ng/L. |
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Interferences
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None Provided |
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Quality Control Requirements
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None. |
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Sample Handling
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None. |
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Maximum Holding Time
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None. |
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Relative Cost
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$51 to $200 |
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Sample Preparation Methods
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