Determination of lead in atmospheric particulates by furnace atomic absorption

Abstract

By use of flameless atomic absorption techniques, it is possible to determine traces of lead in atmospheric particulates in very small samples. The implementation of flameless techniques is greatly simplified by using porous graphite as a filter medium. Using the Woodriff furnace as the atomization device and cups made of porous graphite, one can take an air sample and insert the cup into the furnace for determination with no other chemical or physical treatment. The sensitivity of the determination based on a minimum detectable recorder deflection of 1% is 2.5 X 10-12 gram/sample. This is equivalent to 0.005 ^g/m3 for a 100-cc air sample. When a standard particulate generator was used, the porous graphite compared favorably with Millipore filters. Organic lead, however, was not found to be retained by either type of filter. The techniques described should be readily applicable to other types of flameless devices.