Linear gadolinium-based contrast agents (GBCAs) can cause nephrogenic systemic fibrosis (NSF) in patients with renal insufficiency. NSF is a debilitating disease characterized by the thickening and hardening of the skin and sometimes internal organs. Most cases of NSF are attributed to the administration of the linear agent gadodiamide. To this day, the exact mechanism of the development is unknown, but it is assumed that the prolonged half-life of GBCAs in patients with renal insufficiency plays a crucial role. To further investigate the mechanism of NSF development, tissue from the kidneys and liver of two NSF patients was examined in order to gain insight into possible metabolites. For this purpose, an automated ion chromatography (IC) system coupled to an inductively coupled plasma-mass spectrometer (ICP-MS) is used.

Soluble gadolinium species were first extracted from the tissue thin sections for speciation analysis and the remaining tissue was ashed to allow for total metal analysis. For speciation analysis, different GBCAs were used as standards to quantify the gadolinium concentration across the entire chromatographic run. During total metal analysis, it was observed that some of the extracted soluble gadolinium species could not be analysed by IC-ICP-MS. It was also found that the majority of the gadolinium remained in the tissue and was only analysed after ashing of the whole sample, which indicates a gadolinium deposition in both the liver and kidneys as insoluble gadolinium species.