The present and future of graphite furnace atomic absorption spectroscopy

Abstract

Graphite furnace atomic absorption spectroscopy (AAS) technology has been greatly improved since the late 1970s and the new technology is now being used widely. The chief characteristic of the new technology is its remarkable freedom from interference while retaining the high sensitivity of graphite furnace AAS. Thus, an important goal of continuing furnace research is to identify interferences that persist and, by understanding the causes of residual interference, make further improvements to the system. Several background correction systems have been used. Furnace AAS remains a slow analytical technique, typically about 2 min per analyte and sample. One way to speed throughput is to use simultaneous multielement analysis although this is not easily compatible with the modern furnace. Inherently, the photometric range of furnace AAS has been more limited than, say, inductively coupled plasma but there are now ways to improve the range of furnace measurements. Alternatively, furnace emission provides a potential multielement opportunity, especially if the emission signal is enhanced with an electric discharge. The reduction in matrix interferences increases the opportunity of analyzing solid samples in the furnace. Solid samples may be handled by using well stirred aqueous slurries of finely ground materials. Flow injection analysis, already widely used with flame AAS, provides real potentiality. Perhaps the furnace AAS may become an 'absolute' technique. This will require some changes in the design of the spectrometer and electronic signal handling.