INVESTIGATION OF THE ORDER OF COPPER ATOMIZATION AT THE ABSORBENCY MAXIMUM IN GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY

Two methods to determine the order of the atom formation reaction from the absorbance signal profile are proposed. In one method, the first-order assumption, which is often used to develop various Arrhenius-type plots in graphite furnace atomic absorption spectrometry (GFAAS), is graphically verified by plotting log (A(m)T(m)2 vs log integral-t(m)/x A dt, where the subscript m indicates the value of the subscripted term at the absorbance maximum. The linearity of this plot verifies the first-order assumption. The other method allows one to determine the order of the atom formation reaction at the maximum of the absorbance signal using the equation, n(m) = [GRAPHICS} The order of the atom formation reaction of copper from a pyrolytically coated graphite tube was found to be 0.95 +/- 0.04 by the graphical method, and 1.01 +/- 0.04 by the method of calculation, indicating that the atomization of copper does indeed follow first-order kinetics.