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Sam Ruben | |
|---|---|
| Born | (1913-11-05)November 5, 1913 California, U.S. |
| Died | September 28, 1943(1943-09-28) (aged 29) |
| Nationality | American |
| Alma mater | University of California, Berkeley |
| Scientific career | |
| Fields | Physical chemistry Biochemistry |
| Academic advisors | Ernest O. Lawrence |
Samuel Ruben (bornCharles Rubenstein; November 5, 1913 – September 28, 1943) was an American chemist who withMartin Kamen co-discovered thesynthesis of theisotopecarbon-14 in 1940.
Ruben was the son of Herschel and Frieda Penn Rubenstein – the name was officially shortened to Ruben in 1930. Young Sam developed a friendship with neighborJack Dempsey and became involved with a local boys' boxing club and later, when the family moved across the Bay toBerkeley, he was a successful basketball player atBerkeley High School (Berkeley, California). After achieving his B.S. inchemistry at theUniversity of California, Berkeley, he continued his studies there and was awarded a Ph.D. inphysical chemistry in May 1938. He was immediately appointed instructor in the chemistry department, and became an assistant professor in 1941.[citation needed]
Ruben and colleagueMartin Kamen, aUniversity of Chicago Ph.D. and researcher in chemistry andnuclear physics working underErnest O. Lawrence at theBerkeley Radiation Laboratory, set out to elucidate the path of carbon inphotosynthesis by incorporating the short-lived radioactive isotopecarbon-11 (11
CO
2) in their many experiments between 1938 and 1942. Aided by the concepts and collaboration ofC. B. van Niel, atStanford University'sHopkins Marine Station, it became clear to them that reduction of CO2 can occur in the dark and may involve processes similar to bacterial systems. This interpretation challenged the century-oldAdolf von Baeyer theory of photochemical reduction of CO2 adsorbed onchlorophyll which had guided decades of effort byRichard Willstätter,Arthur Stoll, and many others in vain searches forformaldehyde.
In hundreds of experiments with carbon-11 produced fromdeuterons and boron-10 by Kamen in the Radiation Laboratory's 37-inchcyclotron, Ruben and Kamen, with collaborators frombotany,microbiology,physiology andorganic chemistry, pursued the path of carbon dioxide in plants, algae, and bacteria. Their results, confused by absorption of the products on proteinaceous residues, initially failed to reveal the path of carbon in photosynthesis but succeeded in exciting the interest of scientists worldwide in the search and revelation of metabolic processes, beginning a revolution inbiochemistry and medicine.
Ruben's experiments using 'heavy water',H218O, to yield18
O
2 gas had shown that theoxygen gas produced in photosynthesis comes from water. With nuclear physicists' tenuous prediction of a "long-lived radioactive carbon isotope", Ruben and Kamen pursued several routes that could lead to identification of thecarbon-14 isotope. After several failed attempts, Kamen collected the results of a 120-hourcyclotron bombardment of graphite and trudged in the rain with it to the "Rat House", adjacent both to the chemistry department and to thecyclotron, and Ruben's desk. At 8 am, February 27, 1940, Ruben demonstrated unequivocally that the radioactivity was from carbon-14.[citation needed]
Use of carbon-14 in tracer experiments was hindered by the difficulty measuring the weak beta emission of the radioactive decay and by the onset of World War II that shut off production of the isotope. In 1942 Ruben was assigned to work on war related research away from Berkeley. Further, Kamen was removed from his position at Berkeley due to allegations he was a security risk. Ruben fully realized the potential use of this isotope and was committed to working to elucidate the mechanism of photosynthetic carbon fixation using carbon-14. Instead, Ruben gave all his barium carbonate-14C to chemistry department faculty memberAndrew Benson who began his long series of14
CO
2 fixation experiments to determine the path of carbon in photosynthesis. Only in 1949 did chemistWillard Libby use it to inventradiocarbon dating.
Ruben's recruitment for research in the World War II wartime effort led him to interest in the mechanism ofphosgene as a poisonous gas. With C-11 phosgene (11
COCl
2) prepared by Benson, they studied the combination of phosgene with lung proteins. Following Benson's departure from Berkeley in July 1943, Ruben died September 28, 1943, after a disastrous exposure to phosgene in a laboratory accident the preceding day.
Sam Ruben married Helena Collins West, a fellow chemistry student, during his final semester as an undergraduate at UC Berkeley, on September 28, 1935. They had three children: Dana West Ruben (born November 11, 1938), George Collins Ruben (born April 29, 1941), who became a professor atDartmouth College,[1] and Connie Mae Ruben Fatt (born June 18, 1943).
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