A method for identifying hazardous substances in a printed wiring assembly having a plurality of discrete components, using micro X-ray fluorescence spectroscopy. A micro X-ray fluorescence spectroscopy (.mu.-XRF) and/or X-ray Absorption Fine Structure (XAFS) spectroscopy are used as detecting analyzers, to identify materials of concern in an electronic device. The device or assembly to be examined is analyzed by moving it in the X, Y, and Z directions under a probe in response to information in a reference database, to determine elemental composition at selected locations on the assembly, the probe positioned at an optimum analytical distance from each selected location for analysis. The determined elemental composition at each selected location is then correlated to the reference database, and the detected elements are assigned to the various components in the assembly.