COMPARATIVE INTERFERENCE STUDY FOR ATOMIC-ABSORPTION LEAD DETERMINATIONS USING A CONSTANT TEMPERATURE VS A PULSED-TYPE ATOMIZER

During the one to three seconds necessary to heat commercial electrothermal atomizers to the desired atomization temperature, many reactions take place, and analyte compounds may be lost from the rapidly heating furnace at varying temperatures with varying matrices—often at sub-optimal temperatures with inadequate atomization, since residence times are short. Thus, matrix interferences are common in these pulsed-type atomizers. However, the same solutions, when atomized in a constant temperature furnace (CTF), show no significant matrix interferences. Lack of ruggedness of analytical procedures using pulsed-type atomizers seems to be an inherent limitation, whereas equipment ruggedness limitations of the CTF are amenable to elimination by appropriate attention to engineering aspects of fabrication. Difficult samples representing common matrices reveal the ease of obtaining interference-free results directly with the CTF—and the difficulty, even with pretreatments, of correcting for interferences on a routine basis in pulsed-type atomizers. © 1979, American Chemical Society. All rights reserved.