Development of a novel offline/online separation LC-ICP-MS method for the analysis of the distribution of metals and metal-complexes in aqueous sediment slurries

Abstract

A new method for determining the distribution of trace metals in sediments containing complexing ligands such as EDTA and sediment was developed. This method required the coupling of an LC with an ICP-MS. The method uses an off-line or an on-line separation method prior to the injection of a sediment slurry containing both trace metals and EDTA. A certified estuarine sediment from NIST was identified and characterized as the test sediment to induce sorption of metals from water. The certified estuarine sediment was composed essentially of silica (SiO[subscript 2]). The average concentration of C, H, and N in the sediment was 0.56 %, 0.20 % and 0.14 %, respectively. The LC separation was optimized using a weak anion exchange column containing a polystyrene divinylbenzene trimethylammonium stationary phase with a 5.4 mM sulfuric acid mobile phase. A sorption experiment was conducted, where target trace metals with EDTA are in contact with a sediment slurry. The preliminary results show that the metal sorption kinetics using time-dependent ICP-MS signals could be followed and measured.