ABSTRACT
When determining the source or sources of a contaminant, it is useful to be able to identify as many components as possible. One substance may be used in several locations in the manufacturing plant, but it may be possible to pinpoint its exact source if it is found in conjunction with some other material. Sometimes separations can be made by physically isolating particles or by solvent extrac tions using one of the methods described in Chapter 11. In the case of paints or other filled polymers, these techniques are limited to matrices soluble in some solvent. Supporting evidence may be obtained through polarized-light micros copy (PLM), scanning electron microscopy (SEM), x-ray diffraction (XRD),
energy-dispersive x-ray spectrometry (EDX), micro-Raman spectroscopy, or microchemical tests.
