Koichi Tanaka (田中 耕一, born 1959-08-03 ) 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. In 1983, he graduated from Tohoku University with a bachelor's degree in engineering. After graduation, he joined Shimadzu Corporation , where he engaged in the development of mass spectrometers.

For mass spectroscopic analyses of a macromolecule, such as a protein, the analyte must be ionized and vaporized by laser irradiation. The problem is that the direct irradiation of an intense laser pulse on a macromolecule causes cleavage of the analyte into tiny fragments and the loss of its structure. In February 1985, Tanaka found that by using a mixture of ultra fine metal powder and glycerol as a matrix, an analyte can be ionized without losing its structure. His work was reported for the first time at the Annual Conference of the Mass Spectrometry Society of Japan held in Kyoto, Japan, in May 1987. This phenomenon, referred to as soft laser desorption (SLD), provided the basis for matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/MS). Just after his report, two German scientists, Franz Hillenkamp and Michael Karas , also reported SLD using a small organic compound as a matrix that demonstrated higher sensitivity than Tanaka's method, and they greatly contributed to the development of MALDI. MALDI-TOF/MS is indispensable for life sciences today, especially in the field of proteomics.

External links

• The Nobel Prize in Chemistry 2002
• Nobel Prize Announcement (Shimadzu Corporation)