Oxygen isotope concentration method

Abstract

A method of concentrating the stable oxygen isotopes of 17 O and 18 O by irradiating ozone with light, selectively dissociating an isotopologue of ozone containing an oxygen isotope in its molecule into oxygen, followed by dissociating the ozone and separating the formed oxygen from the non-dissociated ozone. In the ozone photodissociation step, light is radiated onto a rare gas-ozone mixed gas containing ozone and at least one rare gas selected from krypton, xenon and radon is used to selectively dissociate ozone containing a specific oxygen isotope in its molecule into oxygen then the oxygen isotope is separated from non-dissociated ozone and rare gas to concentrate the oxygen isotope present in the separated oxygen.

1 .- 13 . (canceled) 
     
     
         14 . An oxygen isotope concentration method, wherein peroxide molecules containing oxygen isotopes,  17 O and/or  18 O, are photodissociated; thereby increasing the concentration of the oxygen isotope in a photoreaction product. 
     
     
         15 . An oxygen isotope concentration method according to  claim 14 , wherein at least one type of semiconductor laser selected from an InGaAsP semiconductor laser, AlGaInP semiconductor laser, GaAsSb semiconductor laser, CdZnTe semiconductor laser, CdZnSe semiconductor laser, AlGaN semiconductor laser and InGaN semiconductor laser, is used. 
     
     
         16 . An oxygen isotope concentration method according to  claim 14 , wherein the peroxide is at least one type of organic peroxide selected from hydroperoxides, (di)alkyl peroxides, peroxyacids including peracids, (di)acyl peroxides, peroxy esters, peroxycarbonates, peroxydicarbonates, diperoxycarbonates, peroxalates, cyclic peroxides, ozonides and endoperoxides. 
     
     
         17 . An oxygen isotope concentration method according to  claim 14 , wherein the peroxide is at least one type selected from nitrous ester and nitric ester. 
     
     
         18 . An oxygen isotope concentration method according to  claim 14 , wherein the peroxide is diluted with at least one type of solvent selected from carbon tetrachloride, acetone, acetic acid, hexane, toluene and chlorofluorocarbons. 
     
     
         19 . An oxygen isotope concentration method according to  claim 14 , wherein the peroxide is diluted with an organic substance having a double bond. 
     
     
         20 . An oxygen isotope concentration method according to  claim 14 , wherein the photodissociation is prephotodissociation. 
     
     
         21 . An oxygen isotope concentration method according to  claim 14  further comprising:
 (I) a vaporization step, in which a solution prepared by diluting-peroxide having a O—H bond, O—O bond, C—O bond, or C═O bond with a solvent is vaporized under reduced pressure, and then fed into a photoreaction cell; 
 (II) a photodissociation step, in which the peroxide in the photoreaction cell is irradiated with semiconductor laser light having photon energy enough to dissociate the peroxide and wavelength of which corresponding to one of the absorption spectra of a O—H bond, O—O bond, C═O bond or C═O bond, thereby photodissociating the peroxide; and 
 (III) a purification step of the photoreaction product from the step (II), thereby concentrating  17 O or  18 O in one type of molecular species.