Trace element determination in high-salinity water using an online ion imprinted helical tube demineralizer combined with ICP-MS†
Matrix interference is a common problem in the measurement of trace elements in water via ICP-MS. To solve this problem, a novel demineralizer was developed to combine with ICP-MS for determining trace elements in high-salinity water samples, which were filled with a novel ion imprinted material. In the analysis of water samples containing 120 mg L−1 of Ca2+, Mg2+, and Na+, the recoveries of As, Cd, Cu, Mn, Ni, Pb, Sb, and Tl were all maintained between 80% and 120% during the 10 hours of the continuous operation of the demineralizer, with the trueness and repeatability for all elements standing below 3% and 5%, respectively. After the usage of the demineralizer, the detection limits of the method for As, Cd, Cu, Mn, Ni, Pb, Sb, and Tl were reduced to less than one-tenth of its original values. In the analysis of real water samples, a standard substance containing trace elements in the coastal water (CASS-5) and 5 offshore seawater samples were analyzed. The trueness and repeatability for all elements were below 5% and the recoveries were between 85–104%, which all met the requirements of analytical chemistry.