2026/07/01 by R. Klein, C. Gautier, C. Chendo +1
Chemistry · Environmental Science · Chemical Engineering · #Radioactive element chemistry and processing #Environmental Chemistry and Analysis #Chemical and Physical Properties in Aqueous Solutions
paper · doi:10.1016/j.chroma.2026.467293
Radioactive effluents, in particular sludges, are particularly challenging samples to analyse. Before their management in dedicated disposals facilities, quantification of chelating agents potentially present in these matrices, such as EDTA (ethylenediaminetetraacetic acid), is required. In a recent study, a unified protocol was established and validated for the accurate measurement of five chelating agents (NTA/ nitrilotriacetic acid, EDTA, DTPA/diethylenetriaminepentaacetic acid, TTHA/triethylenetetraminehexaacetic acid and gluconic acid) in sludges. This study provides detailed insights into the behaviour of these chelating agents during the overall HPLC-ESI-HRMS analysis process. Based on speciation calculations, some complexes are supposed to be doubly-charged species after sample pretreatment but during LC-MS experiments, due to the ionization process in mass spectrometry, only singly-charged species were detected. This gave a new highlight on the mechanisms involved in HPLC separation and ESI source and showed that attention has to be paid to the analytes speciation when performing LC-MS experiments. Moreover, it permitted to better understand the origin of the heavy chromatographic matrix effects caused by the sample, and counter them by an optimal dilution or the addition of ammonium acetate in the mobile phase. Lastly, a particular behaviour was observed for DTPA complex, transforming from a Ni 2 -DTPA form to a Ni-DTPA one during HPLC separation. A thorough understanding was achieved towards separation mechanisms, matrix effects and speciation changes. This knowledge is crucial for further development on new molecules or types of samples.