Direct determination of metals in solid samples by graphite-furnace atomic absorption spectrometry: Does sample mass influence the analytical results?

In our previous experience on the determination of metals by direct analysis of the solid sample using graphite-furnace atomic absorption spectrometry, it was found that the use of too large or too small mass of sample may lead to erroneous results, even if the analyte content lies within the linear dynamic range. Few references, however, can be found in the literature dealing with this problem. The ANOVA performed on a total of 293 measurements of copper in a Vitamin complex, proves that sample masses smaller than 0.3 mg or larger than 1.1 mg give overestimated and underestimated results, respectively. (C) 1997 Elsevier Science B.V.