THE GRAPHITE FILTER FURNACE - A NEW ATOMIZATION CONCEPT FOR ATOMIC SPECTROSCOPY

A new atomization concept for electrothermal atomic absorption spectro scopy (ETAAS) is proposed and discussed. The basic idea is to form wit hin part of an atomizer a large surface over which the collection of f ine particles of the sample is to be distributed, and to constrain the vapor exit from that part to the analytical zone. For the amounts of analyte which are in the range of ordinary ETAAS, these techniques do not affect the character of atomic vapor release because the surface a rea for the analyte is smaller than that of the vapor passage. However , when there is an excess of matrix, this technique creates the condit ions for matrix vapor saturation which impedes the evaporation. This i n turn restricts the concentration of matrix vapor in the analytical z one and, respectively, limits spectral background and gas-phase chemic al interferences. The concept is realized in the design of a graphite filter furnace. The principle of operation of the atomizer and practic al methods to obtain analytical advantages are discussed and compared, using experimental data.