Analytical techniques selected area diffraction

The toxicity of the mineral is such that quantitative characterization of erionite is extremely important. Samples should be characterized by using one or more of the following techniques (1) powder X-ray diffraction, (2) electron probe microanalysis or inductively coupled plasma-mass spectroscopy, (3) scanning electron microscopy equipped with wavelength dispersive spectroscopy (WDS) and/or energy dispersive spectroscopy (EDS), (4) transmission electron microscopy equipped with WDS and/or EDS and selected area electron diffraction, and (5) similar or better analytical techniques. [Pg.1048]

Optical microscopy (OM), polarized light microscopy (PLM), phase contrast microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM) are the methods normally used for identification and quantification of the trace amounts of asbestos fibers that are encountered in the environment and lung tissue. Energy-dispersive X-ray spectrometry (EDXS) is used in both SEM and TEM for chemical analysis of individual particles, while selected-area electron diffraction (SAED) pattern analysis in TEM can provide details of the cell unit of individual particles of mass down to 10 g. It helps to differentiate between antigorite and chrysotile. Secondary ion mass spectrometry, laser microprobe mass spectrometry (EMMS), electron probe X-ray microanalysis (EPXMA), and X-ray photoelectron spectroscopy (XPS) are also analytical techniques used for asbestos chemical characterization. [Pg.151]