EFFECTIVENESS OF LINEARIZATION OF CALIBRATION CURVES IN ZEEMAN GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY

A theoretical analysis is made of the effect of analytical line broade ning and of non-absorbable radiation in the light source on the shape of concentration curves in Zeeman graphite furnace atomic absorption s pectrometry. These results have been used in a systematic study of the effect of spectrometer slit width and hollow-cathode lamp (HCL) curre nt on linearization of calibration graphs for 11 elements: Ag, Au, Bi, Cd, Co, Cu, Fe, Mn, Ni, Pb, and Sb. The effectiveness of linearizatio n throughout the analytical range covered was estimated experimentally on series of 25-30 solutions. Three solutions in each series were use d as standards for constructing the calibration graph, the others serv ing to evaluate the linearization effectiveness. Increasing the slit w idth and decreasing the HCL current compared to the standard measureme nt conditions have permitted us to reach a sufficiently high effective ness of linearization for all the elements studied, with the exception of Ni. The maximum deviation of experimental points from the linear g raph under optimum conditions does not exceed 6%. The effect of the De lta parameter used in the computational algorithm on linearization eff ectiveness is investigated.