Abstract
The conditions for concentrating trace metallic elements in common salt (12 elements: Al, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, Ti, V and Zn) using an iminodiacetate-chelating resin disk were examined. These elements were determined by means of inductively coupled plasma atomic emission spectrometry (ICP-AES). Moreover, the amounts of trace metallic elements in common salt were measured under the obtained conditions. As a result, although the 12 elements in water were concentrated simultaneously at pH 4.5, the recovery of some elements (Cd, Mn and Pb) decreased due to the presence of the major components (NaCl, Ca and Mg) of common salt. These elements could be concentrated at pH 8.8. The minimum determination limit of this method was several μg/kg for many elements, when 50 g of sample was processed. The coefficient of variation for repeated measurement of 500 ml of prepared solution added with 2 μg of each element was 5% or less. As a result of measuring trace metallic elements in common salt under the measurement conditions obtained from these above experiments, the determination of the concentrations of many elements was found to be possible. For elements (Cu, Fe, Ni, Ti and Zn) investigated under two pH conditions (pH 4.5 and pH 8.8), the determined values were almost in agreement, and the values for elements of high concentration were in good agreement with the results of direct analysis by ICP-AES.
