Trajèe Stafilov and Dragica Zendelovska
Institute of Chemistry, Faculty of Science, Sts. Cyril and Methodius University,
POB 162, 91000 Skopje, Macedonia
A rapid method was developed for the extraction of cobalt, copper, lead
and nickel from dissolved mineral samples by sodium diethildithiocarbamate
into methylisobutyl ketone and their determination by Zeeman electrothermal
atomic absorption spectrometry. The matrix interferences were investigated
and results show that Ca (as matrix element) tends to decrease absorbance
of investigated elements. Therefore, a separation of Co, Cu, Pb and Ni
from the solution obtained by dissolution of gypsum in HCl was suggested.
Standard addition technique was used for the evaluation of data and the
method was tested using certified reference materials. The standard deviation
(s) is 4 ng·g-1 for Co, 17 ng·g-1 for Cu, 8 ng·g-1 for Pb and 7 ng·g-1
for Ni. The detection limit of the method, calculated as 3s of the blank,
was found to be 12 ng·g-1 for Co, 51 ng·g-1 for Cu, 24 ng·g-1 for Pb and
21 ng·g-1 for Ni.