Development of a HPIC-ICP-MS method for the quantification and speciation of gadolinium-based contrast media in surface waters†

Abstract

Over the last few decades, numerous speciation methods involving hyphenated ICP-MS strategies have been developed to study gadolinium-based contrast agents (GBCAs), whose concentrations are steadily increasing in surface water in France, Europe and around the world. Most of these methods involve the extensive use of organic solvents and often require the use of an additional aerosol desolvation module. Here, a new sensitive chromatographic method has been developed to study the speciation of the six GBCAs currently marketed in France (i.e. Gd-DOTA, Gd-BT-DO3A, Gd-HP-DO3A, Gd-DTPA-BMA, Gd-DTPA and Gd-BOPTA). This HPIC-ICP-MS method, involving the use of an anion-exchange column, allows the separation of the charged GBCAs in less than 15 min, while using only 2% of methanol in the eluent and a standard ICP-Q-MS configuration. The detection limits obtained, ranging from 2 to 5 ng_Gd L⁻¹, are comparable to reference methods in the literature and are therefore well suited to environmental studies. An environmental application has been successfully carried out on water samples from the Marque River (Northern France), which is affected by the presence of numerous WWTPs. This application highlights the fact that GBCAs account for over 90% of Gd pollution in river water.