Prof. Yoshida received the Doctor of Science degree in chemistry from Tokyo Institute of Technology in 1984. He was with the Mitsubishi–Kagaku Institute of Life Sciences, Toyama University and with Nagoya University, and has been a full professor in charge of two environmental departments of Tokyo Institute of Technology since 1998, and is also a principal investigator at the Earth–Life Science Institute. He is now a vice director of the Inter-Departmental Organization for Environment and Energy, a core faculty of the leading graduate school selected by the Ministry of Education, Culture, Sports, Science and Technology, a vice president of the Geochemical Society of Japan, and president of the International Symposium on Isotopomers.