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 Equipment

 

Future Equipment

EPA has purchased new pieces of equipment to give researchers the ability to conduct increasingly advanced studies in their effort to improve the health of the public and the environment.

Confocal Microscope
The confocal microscope is used to increase optical resolution and contrast of a micrograph. Confocal microscopy is a key laboratory technique, especially in life science and material science applications. Conventional fluorescence microscopes flood the whole specimen with light, while the confocal microscope uses point illumination; that is, only one point of the sample is illuminated at a time. Images taken with a confocal microscope are much better than with wide field fluorescence microscopes.

The confocal microscope can produce 2D and 3D images, but long exposures are often required due to the increased resolution associated with point illumination. The confocal microscope is great for 3D imaging and surface profiling of samples.

 

Current Equipment

EPA uses a variety of AMSARC equipment to test solids and liquids.

Atomic Force Microscope (AFM)
The AFM is used to analyze biological samples, membranes, powders, and solids, as well as synthetic solids. Its functions include determining the magnetic properties of a sample, measuring the reactivity of a surface, and viewing biological membranes. Image: Atomic Force Microscope

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Carbon-Sulfur Analyzer
With the carbon-sulfur analyzer, researchers can examine solid samples with total masses of less than 0.1 gram. The analyzer can measure total carbon (inorganic and organic) and total sulfur (sulfate, sulfide, and organic) in solid samples. Image: Carbon-Sulfur Analyzer

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Coulometric Carbon Analyzer
The coulometric carbon analyzer is used to measure the total inorganic carbon content of solids and liquids. Image: Coulometric Carbon Analyzer

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Cross-Section Polisher
The JEOL cross-section polisher uses argon to produce an ion beam that sweeps the surface of the sample being polished. This is a nonmechanical means of polishing the cross-sectional face of a sample. The result is a highly polished face on which even the finest details of the sample have been preserved. It is used primarily for delicate samples that may tear away or that tend to smear with mechanical polishing. Image: Cross-Section Polisher

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Light/Stereo Microscope
The light/stereo microscope allows researchers to view the structures of living cells, minerals, corroded metals, semiconductors, and many other materials by using either light or dark microscopy methods. Image: Light/Stereo Microscope

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Sample Preparation Equipment
Sample preparation equipment includes saws, sanding equipment, ball mills, hydraulic presses, mortars and pestles, and sieves needed to encapsulate solid specimens. Image: Sample Preparation Equipment

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Scanning Electron Microscope (SEM)
With Energy Dispersive Spectroscopy (EDS)
The JEOL 5800LV SEM with an Oxford EDS is used to perform structural and elemental analysis on vacuum-compatible solids, bulk materials, fibers, powders, and biological samples. Samples that are nonconductive must be coated with conductive materials, such as gold or carbon, before being viewed; or, the samples may be viewed on a low-vacuum setting to reduce electron charging of the sample. Ultimately, the SEM with EDS helps researchers identify surface structures and the elemental composition of micron-sized features. Image: Scanning Electron Microscope with Energy Dispersive Spectroscopy

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Scanning Electron Microscope (SEM)
With Wavelength Dispersive Spectroscopy (WDS)
Because of its versatility and the wide range of information it can provide, the scanning electron microscope is often the preferred starting tool for analytical microscopy. With a SEM, a focused beam of high-energy electrons is scanned over the surface of a material. The electron beam interacts with the material, causing a variety of signals—secondary electrons, backscattered electrons, X-rays, photons, etc.—each of which may be used to characterize a material with respect to specific properties. The signals are used to modulate the brightness on a display cathode ray tube, thereby providing a high-resolution map of the selected material property.

The JEOL 6490LV SEM is enhanced with a WDS, as well as with a high-throughput analytical drift detector for electron dispersive spectroscopy (EDS). These spectrometers allow the simultaneous collection of elemental data and provide a finer resolution of light and trace elements. This powerful system helps researchers to characterize finer details of samples and sample composition.

Image: Scanning Electron Microscope (SEM)
With Wavelength Dispersive Spectroscopy (WDS)

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Scanning Transmission Electron Microscope (STEM)
With a scanning transmission electron microscope (STEM), the electron beam is raster-scanned across the material. (A raster scan is the pattern of image storage and transmission used in most computer image systems.) In combination with an electron dispersive spectrometer system, the STEM system produces a variety of electron and X-ray signals that may be used for compositional analysis.

The 200-kilovolt STEM operates at a resolution of 0.4 nanometers. It is used for examination of biological and material samples with similar applications to the transmission electron microscope, but with the addition of a scan head that rasters the beam across the sample.

Image: Scanning Transmission Electron Microscope

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Solids Carbon Analyzer
The solids carbon analyzer is used to measure the total organic and inorganic carbon content of solids. Image: Solids Carbon Analyzer

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Transmission Electron Microscope (TEM)
Researchers use the JEOL 1200EX II TEM to analyze nanoparticles, thin films, and biological specimens. With this microscope, researchers can determine the morphology and chemical composition of particles, investigate defective structures and interactions, and view the ultra-structure of biological and material samples. Image: Transmission Electron Microscope

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X-Ray Diffractometer (XRD)
X-ray diffraction is a versatile, nondestructive technique used to identify the crystalline phases present in solid materials and powders. It is also used to identify structural properties (stress, grain size, phase composition, crystal orientation, and defects) of the phases. The technique uses a beam of X-rays to bombard a specimen from various angles. The X-rays are diffracted as they are reflected from successive planes formed by the crystal lattice of the material. By varying the angle of incidence, a diffraction pattern emerges that is characteristic of the sample. The pattern is identified by comparing it with tens of thousands of reference patterns contained in an internationally recognized database. Image: X-Ray Diffractometer

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X-Ray Fluorescence (XRF) Analyzer
The XRF is used to analyze pressed powders of solid materials. Researchers use this analyzer to conduct quantitative elemental analysis of a sample. Qualitative elemental scans can also be performed on flat or powdered samples. Image: X-Ray Fluorescence

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Zetasizer Analyzer
The zetasizer analyzer allows researchers to analyze suspended particles and microbes in liquid. Researchers can determine the charge of an ion in a sample and investigate how ions will interact with or repel other ions. Image: Zetasizer

Office of Research & Development | National Risk Management Research Laboratory | Risk Management Water Research


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