1979 Volume 28 Issue 6 Pages 347-351
Several metals show severe interferences in the determination of lead and cadmium by graphite furnace atomic absorption spectrometry. To suppress these interferences, the matrix modification was investigated, i.e., the matrix is changed into the harmless form by the addition of proper chemical compound into the graphite furnace. The addition of several ammonium salts was examined for this purpose. The added volume of these ammonium salts solution was 40μl for 20μl of sample solution. In the case of the atomic absorption of lead, the addition of 20% ammonium phosphate solution overcomes the interferences of any of foregin metal ions. In the case of cadmium determination, even the addition of 10% ammonium sulfate solution was effective. This method was applied to the direct determination of lead and cadmium in smelting process water and sea water. Results gave a good agreement with those obtained by flame atomic absorption spectrometry combined with the solvent extraction.
