DEVELOPMENT OF THERMO-AAS INSTRUMENTATION TO EVALUATE THE VOLATILIZATION OF METALS FROM DIFFERENT MATRICES

Thermoatomic absorption spectrometry (TAAS) has been found to be a pro mising new technique for evaluating the volatility of metal compounds from complex matrices even at trace levels. Two TAAS instruments are d escribed and evaluated, one based an the principle of direct combinati on and the other on the principle of indirect combination of graphite furnace evaporator, flame atomic absorption detection, and IR-optical pyrometric temperature measurement. With the two different setups it w as possible to carry out measurements in the atmosphere of a flame or in a controlled inert atmosphere and also to do measurements in graphi te, in pyrolitic graphite, or in a quartz-lined graphite sample holder . The instruments were tested with different cadmium compounds used in solid form and in aqueous solution and the TAAS curves were compared to TG/DTG curves. (C) 1995 Academic Press, Inc.