Metrology for the harmonisation of measurements of environmental pollutants in Europe

To achieve the European Green Deal’s goal of “a toxic-free environment”, efficient and sensitive techniques are required to monitor both radioactive and stable environmental pollutants. Two such techniques are radiometry, which measures radioactivity, and mass spectroscopy (MS), which measures the mass-charge ratio of particles and allows exact isotope compositions to be detected, even at low concentrations. Although radiometry techniques are well-established, there is a lack of traceability and quality control for MS. Additionally, mass spectrometers require validation using traceable reference materials, as known mass biases within the technique must be accounted for. Multi-element references are often unavailable and single-element references only exist for a limited number of species.

This project has developed at least one radioactive reference material, for use in inter-laboratory comparison, and aqueous reference materials for several stable elements to be used for calibration. It has also established and compared radioactive pollutant detection limits for different types of mass spectrometer, assessing relative performance and establishing limits for use in environmental regulations. It used inductively coupled plasma mass spectroscopy (ICP-MS) to develop traceable methods for measuring stable isotope ratios and applied them to more commonly available MS techniques, producing sample processing, uncertainty, and mass bias recommendations. By bridging the gap between radiometry and MS, this project will accelerate the uptake of MS techniques, reducing detection limits and improving response times for pollution incidents. This will reduce human and environmental exposure to radiation and toxins and provide support for the goals of the Green Deal.