Development of ICP-MS and ICP-OES methods for determination of gadolinium in samples related to hospital waste water treatment

A suitable analytical method making possible the determination of Gd and other rare-earth elements in samples related to hospital waste water treatment was sought with regard to various aspects of the experiment aimed at monitoring the fate of Gd-based contrast agents in the aquatic environment. The discrepancies and pitfalls of the proposed methodology were considered, resulting in a functional experimental plan. The inductively coupled plasma mass spectrometry (ICP-MS) method was used for the determination of Gd and other rare earth elements in river and hospital waste water and algae Parachlorella kessleri cultured in laboratory experiments. The sample preparation of algae prior to analysis was optimised. The ICP-MS method was validated using a recovery study, sample blanks, reference materials, and comparison with the inductively coupled plasma optical emission spectrometry (ICP-OES) method. The ICP-MS method was confirmed as suitable for monitoring the biosorption/bioaccumulation of Gd in algae and for evaluating the Gd anomaly in hospital waste water and rivers of Eastern Bohemia. In the laboratory experiments, the bioconcentration factors were calculated (all in L kg(-1)) for algae cultured in inorganic Gd salt (about 1100), in waste water from a magnetic resonance workplace (2300) and in waste water from a hospital waste water treatment plant (4400). A positive Gd anomaly in waters from the river Elbe in the Eastern Bohemia region was found less pronounced in the areas unaffected than in the areas affected by waste waters from hospital. (c) 2016 Institute of Chemistry, Slovak Academy of Sciences