Direct Analysis of Solid Samples by Flameless Atomic Absorption Spectrometry. Application to Some Siliceous Materials

Fundamental operational parameters like temperature, weight of samples, and time of drying, charring, and atomization are optimized for direct determination of calcium, magnesium, and iron in siliceous materials (feldspar and lime). The use of low intensity absorption lines together with the dispersion of the samples in a graphite matrix, allows the technique to be applied to materials containing up to 2.1% CaO, 0.36% MgO, and 0.75% Fe2O3. The results are compared with those obtained by flame and graphite furnace atomic absorption spectrometry using standard solutions. The correlation found between the three techniques and the reported composition of NBS samples are highly satisfactory.