石墨炉原子吸收光谱分析法的原子化效率和特征量

CHARACTERISTIC MASS AND ATOMIZATION EFFICIENCY OF GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY

Measurements of peak height and peak area characteristic masses and atomization efficiency for 7 elements (Ag, Bi, Cd, Cr, Ga, Ge and In) have been studied. The m0(i)(exp) values are compared with theoretical data, m0(i)(cal), to assess the effect of temperature on the correction factor of theorization for characteristic mass value (alpha = m0(i)(cal) m0(i)(exp)), the peak height and the peak area atomization efficiencies (betap and betai). The peak area atomization efficiency (betai) was equal to the correction factor of theorization for characteristic mass value (alpha) times tauD/tauR value. The tauR was value experimentally measured of atomic residence time and the tauD value calculated from rD = l2/8D. The betai value of elements always are smaller than the alpha values because the tauD/tauR values is less than one for most elements in the operating conditions. Past of the analyte vapours is readsorbed by the heated tube wall at high temperature and reevaporation of the adsorbed analyte followed by diffusion account for the larger atomic residence time and it appeared that the tauR value was larger than the tauD in graphite furnace.