Light Element Microanalysis

The light element regime traditionally defined as the elements Be through F (Z = 4 to 9) has posed many difficulties for the analyst. Poor detectability due to low count rates caused by insufficient beam current at low voltage and small spot sizes has made microanalysis very difficult Adequate matrix correction procedures are just being developed and quantification is difficult without very good standards. Contamination of the sample during analysis often makes the results questionable. These problems are slowly but surely being corrected in today’s modern electron microprobes. New WDS crystals and recent ultra-thin-window (UTW) have contributed to improved detectability; modern electron columns have much better low-voltage performance; and finally, today’s SEMs and microprobes are designed with anticontamination devices. However, with all these improvements, the measurement and subsequent quantification of light elements is far from routine. This laboratory will illustrate operational aspects of light element analysis background measurements, peak overlap problems, and quantitation techniques. More details may be found in SEMXM, Chapter 8.