New Mexico Geological Society Annual Spring Meeting — Abstracts

Gadolinium (Gd) contamination in water bodies, largely due to the discharge of gadolinium-based contrast agents (GBCAs) from MRI procedures, has emerged as an environmental and public health concern. After being excreted by patients, GBCAs pass through wastewater treatment systems and enter surface and groundwater, potentially exposing humans to more toxic forms of Gd. Accurate measurement of Gd speciation is essential, yet standardized protocols for sample collection and preservation are currently unavailable. This research focuses on assessing the impact of preservation methods—temperature, pH adjustment, and filtration—on Gd speciation stability in environmental water samples. Deionized water, tap water, and Rio Grande River water, will be tested at different time points to analyze Gd concentrations and speciation using ICP-MS and IC-ICP-MS. The samples will be spiked with Gd³⁺ and four GBCAs to assess their behavior under different conditions.

Preliminary ICP-MS results indicate that preservation methods significantly influence Gd recovery across different water types. River water samples demonstrated relatively stable total Gd concentrations across temperature treatments, while tap and distilled waters showed greater variability. Measured total Gd concentrations were consistently higher in acidified samples across all temperatures and water types, whereas unacidified samples often showed lower recoveries, especially at colder temperatures and in distilled water. Additionally, acidified samples tended to align more closely with the spiked concentration, indicating that acidification enhances Gd recovery and contributes to the stability of Gd species during sample processing. These patterns suggest that both preservation conditions affect the extent to which added Gd remains in solution or is detectable.

This research will provide evidence-based guidelines for the preservation of Gd in environmental water samples, enabling more accurate monitoring of Gd contamination. Establishing these protocols will enhance the understanding of Gd contamination, supporting more effective risk assessments and the creation of regulatory guidelines to manage water quality and protect public health.