Preconcentration of Co, Ni, Cd and Zn on naphthalene–2,4,6-trimorpholino-1,3,5-triazin adsorbent and flame atomic absorption determination

A preconcentration method was developed for the determination of trace amounts of Co, Ni, Cd and Zn by atomic absorption spectrometry. The method is based on the retention of the metal cations by naphthalene–2,4,6-trimorpholino-1,3,5-triazin adsorbent in a column. The adsorbed metals were then eluted from the column with hydrochloric acid and the Co, Ni, Cd and Zn were determined by flame atomic absorption spectrometry. The optimal extraction and elution conditions were studied. The effects of diverse ions on the preconcentration were also investigated. A preconcentration factor of 250 for Co(II), Ni(II) and Zn(II), and 400 for Cd(II) can easily be achieved. Calibration graphs were obtained and the detection limits of the method for Co(II), Ni(II), Cd(II) and Zn(II) were 0.51, 0.49, 0.17 and 0.10 ng mL, respectively. The relative standard deviations (RSD) of 0.37–2.31 % for Co, 0.37–3.73 % for Ni, 2.20– 2.40 % for Cd and 1.50–2.56 % for Zn were obtained. The method was also used for the simultaneous preconcentration of these elements and the method was successfully applied to their preconcentration and determination. The method was applied to the determination of Co, Ni, Cd and Zn in several real samples.