Research showcase
Mercury analysis method developed by NIMD
Since the outbreak of Minamata disease, various studies and investigations have been conducted around the world to evaluate mercury accumulation and to elucidate the health effects of mercury exposure. As part of these efforts, many analytical methods of mercury have been developed around the world, and knowledge of mercury contained in various media (air, water, soil, and organisms) has been accumulated. Since mercury is widely present in the environment, mercury analysis in various media requires pretreatment and analytical methods specific to the target sample, as well as analysis of different chemical forms of mercury.
NIMD-A method (commonly known as Akagi Method)
The NIMD-A method was established at the National Institute for Minamata Disease, led by Dr. Hirokatsu Akagi, former Director of the Department of International Affairs and Research, and is applicable to various samples such as biological samples (fish, hair, etc.) and environmental samples (water and soil). It consists of a total mercury analysis based on wet decomposition and a methylmercury analysis based on solvent extraction using dithizone. Mercury is detected by a reducing vaporization-semi-automatic atomic absorption spectrometer and a gas chromatograph-electron capture detector, respectively.
About the "Akagi's method" manual
Both in and outside of Japan, there is a growing call for techniques that are capable of analyzing not only total mercury, but also methylmercury, for the purpose of more accurate risk assessment. The "Mercury Analysis Manual" (so-called the Akagi's method manual) was put together by the "Mercury Analysis Manual" Development Council (chaired by Tsuguyoshi Suzuki) and was published by the Ministry of the Environment in the hope that Akagi's method, which has been presented on a variety of situations and is highly valued internationally as well, can yield practical applications on an even broader scale.
NIMD-B method
The NIMD-B method is a simple analytical method for mercury in biological samples (fish, hair, etc.). This method can measure both total mercury and organic mercury in the same biological sample using a single apparatus. It is also possible to analyze both total mercury and organic mercury with a single type of mercury standard solution (same ruler for analysis). Furthermore, there is no need for complicated pretreatment of samples, and since mercury detection is performed by a direct thermal decomposition-gold amalgamation-CVAAS, no hazardous waste fluid is generated during analysis.