ABSTRACT
This chapter contains a set of powder X-ray diffraction patterns of well characterized polychlorinated dibenzo-p-dioxins (PCDD's) and polychlorinated dibenzofurans (PCDF's). The powder X-ray diffraction patterns were recorded by a Rigaku D/Max automated wide-angle diffractometer with a 12-kW rotating anode and a Phillips Norelco (XRG-3000) generator and goniometer. The samples for the powder X-ray diffraction (PXRD) work were mounted on a microscope slide via double-stick tape. The mathematical relationship between known PCDD and PCDF single-crystal structure determinations and their PXRD patterns provides a basis to make rapid and conclusive isomeric assignments by PXRD. In several cases, such as the 1,2,3,7,8,9-chlorinated dibenzo-p-dioxin, the PXRD patterns are in good agreement with patterns calculated from known PCDD crystal structure determinations and other reported PXRD patterns. In the absence of "validated" PCDF and PCDD standards, PXRD patterns of unknown or suspect PCDF's or PCDD's may be compared to the reported PXRD patterns.
