ANALYSIS OF IONS PRESENT AT LOW CONCENTRATIONS IN SOLUTIONS WITH OTHER AT HIGHER CONCENTRATIONS

摘要

The invention is a process of selectively and quantitatively removing andconcentrating at least one selected ion present in low concentration withother ions in higher concentration in a multiple ion solution. The methodcomprises bringing a complexing agent for the selected ion(s) into contactwith a sufficient determined quantity of said multiple ion solution to removeand concentrate the selected ion(s) from the multiple ion solution; removingthe multiple ion solution, from which the complexing agent has been removed,the selected ions from the complexing agent having the selected ion(s)complexed therewith, bringing the complexing agent complexed with selectedion(s) into contact with a determined quantity of receiving liquid to breakthe complex and remove the selected and concentrated ion(s) from thecomplexing agent therein, and determining the concentration of selected ion(s)in said receiving liquid from which the concentration of selected ion(s) inthe multiple ion solution can be calculated. The metal ions in lowconcentration are often heavy metal ions, such as lead ions, and the processfinds particularly advantageous utility in the determination of lead contentin ppb in drinking water.The preferred apparatus for carrying out the process is a column packedwith silica gel or silica-bonded macrocycle as the complexing agent which ispreferably selected from the families consisting of