Comparable measurement results for mercury in air


Robust, reliable and traceable measurements of mercury are essential to enable global efforts to reduce the concentration of mercury vapor in the environment, to comply with regulation and to protect human health.

During GAS Analysis 2019 (June 18 – 20, 2019, Fokker Terminal, The Hague, The Netherlands) Iris de Krom will present research results regarding traceability for mercury measurements (11:45 – 12:10 on Tuesday 18 June 2019, Session “Enhancing health, safety and the environment”). For more information about GAS Analysis 2019 visit:

GAS Analysis 2019 will be a major networking opportunity. Please use this opportunity and get into contact with VSL! Visit us in our booth (number 25) to hear about our mercury facilities and all our other services.

Mercury is a naturally occurring element in the earth crust and it is the only metal which is liquid at room temperature, therefore it is also known as quicksilver. Primarily because of human activities, mercury ends up in the environment. Current levels in the atmosphere are up to 5 times above natural levels. Because of its toxicity mercury poses one of the largest current threats to human, animal and environmental health across the globe. Worldwide, initiatives are taken to reduce the mercury burden on the environment, and related regulations become ever more stringent to comply with. To enable this, robust, reliable and traceable measurements of mercury are essential.

To provide traceability for mercury measurements in emission sources and the atmosphere VSL has developed a mercury vapour generator, which can be used as a calibrator of measuring equipment. This vapour generator is directly traceable to the kilogram, the SI measurement unit of the mass. Currently this is the only primary elemental mercury vapour generator available and as a National Metrology Institute (NMI), VSL expects this facility to play a key role in enabling the reduction of the mercury burden on the environment.

At GAS Analysis 2019, our colleague Iris de Krom will present the results of the full characterisation of the mercury generator, which is based on diffusion according to ISO 6145-8. As a benchmark the recent mercury measurement comparison between current calibration facilities maintained by NMIs and equipment manufacturers will be shown. This comparison made use of sorbents tubes loaded with mercury amounts ranging from 2 ng to 1000 ng.

Apart from its elemental form, mercury also occurs in the environment in oxidized forms. These forms are extremely reactive and can be transformed into other species such as methylmercury, which is the most toxic mercury species because of its bioaccumulation in aquatic systems. Within the “Metrology for oxidised mercury” (MercOx) project, under the European Metrology Programme for Innovation and Research, VSL’s primary standard is used to establish a traceable calibration methodology for the most important oxidised mercury-containing species, especially for HgCl2. A concise overview and the first results will be shown in this presentation. For more information about the MercOx project visit: