Different sample treatments for the determination of ICM-XR in fish samples followed by LC-HRMS.

Iodinated X-ray contrast media (ICM-XR) are a group of pharmaceuticals widely used in medicine. Due to their low biodegradation rate, which makes their removal at wastewater treatment plants difficult, and the high doses at which they are administered, they have been detected in aquatic environments. In the present paper, a method for the quantitative determination of a group of ICM-XR in different fish species was developed and validated for the first time. Two extraction techniques were compared: pressurised liquid extraction (PLE) and QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe), with PLE being selected, followed by liquid chromatography-high resolution mass spectrometry. In addition, several clean-up strategies were evaluated. The optimised method provided PLE recoveries ranging from 60% to 88% and limits of detection ranging from 5ng/g to 25ng/g (dry weight). The method was applied in order to evaluate the presence of the selected ICM-XR in different fish species.