Mieczysław Zieliński1, Arthur Fry2, Agnieszka Zielińska1, Nives Ogrinc3, Halina Papiernik-Zielińska1, Ivan Kobal3
1Faculty of Chemistry, Jagiellonian University, 3 Ingardena Str., 30-060 Cracow, Poland,
2Fulbright College of Arts and Sciences, Department of Chemistry and Biochemistry, 115 Chemistry Building, University of Arkansas, Fayetteville, AR 72701, USA,
3J. Stefan Institute, SI-1000 Ljubljana, Jamova Str. 39, Slovenia
Carbon-13 fractionation in the oxidation of sodium propionate of natural isotopic composition with permanganate in water solution and with manganate in alkaline solution has been investigated and compared with carbon-14 kinetic isotope effects in the oxidation of (3-14C) - and (2-14C) propionate with permanganate. The experimental carbon-13 isotope ratios, R(13C/12C)cumul., corrected for dilution of R(13C/12C)a by carbon dioxide derived from all external sources and by carbon dioxide derived from (C-1) and from (C-3) of propionate at its complete and partial oxidations, used for calculation of 13CaKIE, provided the carbon-13 isotope effects corresponding to initial oxidation of alpha carbon, which correlate well with (2-14C) KIE determined previously, (k12/k13 -1)´100 @ 1/2(k12/k14 -1)´100 @ 1/2(4.6±0.3) at 373 K. The possibility of extension of isotope ratio measurements, using modern double collector mass spectrometers, from geochemical, biomedical, agriculture and environmental research to carbon-13 isotope effects studies in chemical organic reactions is briefly discussed.