Determination of cobalt, copper, lead and nickel in gypsum by Zeeman electrothermal atomic absorption spectrometry

A rapid method was developed for the extraction of cobalt, copper, lead and nickel from dissolved mineral samples by sodium diethildithiocarbamate int o methylisobutyl ketone and their determination by Zeeman electrothermal at omic absorption spectrometry. The matrix interferences were investigated an d results show that Ca (as matrix element) tends to decrease absorbance of investigated elements. Therefore, a separation of Co, Cu, Pb and Ni from th e 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.