Koichi Tanaka

Chemist, born in Toyama, N Honshu, Japan. He studied at Tohoku University (BEng 1983), later joining the Shimadzu Corporation. He shared the 2002 Nobel Prize for Chemistry for the development of soft desorption ionization methods for mass spectrometric analyses of biological macromolecules.

Koichi Tanaka (田中 耕一, born August 3, 1959) is a Japanese scientist who won the Nobel Prize in Chemistry in 2002 for developing a novel method for mass spectrometric analyses of biological macromolecules.

Tanaka was born and raised in Toyama, Japan.

For mass spectrometry analyses of a macromolecule, such as a protein, the analyte must be ionized and vaporized by laser irradiation. His work was filed as a patent application in 1985, and after the patent application was made public reported at the Annual Conference of the Mass Spectrometry Society of Japan held in Kyoto, Japan, in May 1987 and became known as soft laser desorption (SLD).

However, there was some criticism about his winning the prize, saying that contribution by two German scientists, Franz Hillenkamp and Michael Karas was also big enough not to be dismissed, and therefore they should also be included as prize winners. Also Tanaka's SLD is not used currently for biomolecules analysis, meanwhile MALDI is widely used in mass spectrometry research laboratories.

However, a major counterargument is that a prize should be awarded to someone who made a real breakthrough, and according to the press release for the prize, the committees does not highly recognize the job of Karas et al. Further argument is that, as Karas and Hillenkemp also recognized Tanaka's work in their paper in 1988, the prize to Tanaka should be accepted without controversy.