B Appendix Comparison of Atomic Spectroscopic Analytical Techniques

B APPENDIX COMPARISON OF ATOMIC SPECTROSCOPIC ANALYTICAL TECHNIQUES 

Metal and metal alloy producers and materials research laboratories routinely use spark and arc emission spectrometry and GD spectrometry has been gaining in popularity because it cau analyze nonconducting solids directly. It is difficult to make direct sensitivity and accuracy comparisons between AAS, ICP, ICP-MS, and the arc/spaik/GD methods, since the latter techniques have sensitivities based on solid samples (limits of detection [LODs] in pg/g) and the former are solution techniques (LODs in pg/mL). While the solution DLs of GF or ICP may appear to be better than arc/spark or GD, the actual dilution factor for a real solid sample needs to be considered to compare the techniques for analysis of solids. 

FAAS is an excellent choice for a small laboratory. The instrumentation is relatively inexpensive and easy to operate. FAAS is a mature technique with many published textbooks, applications, and comprehensive guides for analysis and method development (the cookbooks from instrument manufacturers). Spectral interferences are few and well documented. Flame AAS instrumentation is also a platform for CV Hg and HG determination of As, Se, and T1 by AAS, so the instrumentation is a staple of environmental laboratories. On the negative side, the refractory elements like boron, tungsten, zirconium, and tantalum are difficult to determine because the flame is not hot enough to atomize these analytes. The low temperature of the flame results 

Skills required to develop methods and interpret data Analytical interferences Difficulties with contamination 

The emission signal can be recorded for all elements of interest either simultaneously or in rapid sequence, thus making ICP-OES much faster than AAS techniques if many elements must be determined in each sample and requires less sample volume in the process. The linear working range for ICP-OES is much greater than that of AAS, so trace to major components of a sample can often be determined at the same time. However, the measurement of analyte emission at high temperature requires a monochromator of better resolution than required for AAS thus, ICP-OES 

---