Each field of electron microprobe analysis has its own specific analytical difficulties. Problems relating to the analysis of geologic materials can be primarily attributed to the fact that the samples are nonconductive, some are unstable under the beam, and they have a complex matrix. There are various techniques to solve these analytical problems, but the selection of appropriate standards is one of most important factors.
In study of geologic materials a convention prevails that the summation approximates 100%. For most analyses summation is an indication of the quality of analysis, although some elements could be over or under corrected. Significant progress has been made in developing correction procedures, yet some fundamental parameters still are not well known, and the results will vary depending on which procedures or fundamental parameters are used. One of the most practical solutions to eliminate significant matrix effects is to select reference materials with a close composition to the unknown.