Metrology for traceable protocols for elemental and oxidised mercury concentrations

Environmental mercury poses a threat to human, animal and environmental health. Emission levels are regulated by legislation such as the Industrial Emissions, Air Quality and Waste Incineration directives and the Minamata Convention. Currently it is not possible to defensibly establish regulatory specifications for concentration levels in European directives as mercury gas generators, used in the field to monitor the levels of elemental and oxidised mercury, are not certified against primary standards. This lack of traceability adversely affects the accuracy and confidence in measurements.

Building upon EMRP projects PartEmission and MeTra and EMPIR project MercOx validated protocols for elemental gas generators have been developed based on direct and indirect comparison with the primary mercury gas standard, allowing SI-traceable certification for these instruments. A protocol for certification of oxidised gas generators has also been established at both low (atmospheric) and high (industrial emission) levels and the performance of at least three commercial elemental and oxidised generators will be characterised. At the end of the project in 2023 results will input into new and existing standards, allow traceable measurements of mercury in the environment, meet the obligations of legislation and protect human health.