3.6. Effect of matrix ions
The effects of possible matrix ions present in samples on the recoveries of the studied elements were also examined by adding the known concentration of each matrix ion to the model solution containing the studied trace elements. The tolerated amounts of each ion were the concentration values tested that caused less than 5% alteration in the absorbance. As can be seen from Table 1, the ions commonly present in natural samples did not interfere under the experimental conditions used (recoveries ⩾95%). These results indicate that the proposed preconcentration/separation method for the studied trace elements could be applied to various samples.