Photolysis Study of Perfluoro-2-methyl-3-pentanone under Natural Sunlight Conditions

摘要

The UV-vis and infrared absorption cross sections of perfluoro-2-methyl-3-pentanone (CF_3CF_2C(O)CF(CF_3)_2,1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone),has been obtained,and a photolysis study was carried out under natural sunlight conditions in the European simulation chamber,Valencia,Spain (EUPHORE).The photolysis loss rate,J_(photol),equaled (6,4 +- 0.3) x 10~(-6) s~(-1) in the period of 10-14 GMT,July 14,2003 in Valencia (0.5 W,39.5 N) and corresponded to an effective quantum yield of photolysis of 0.043 +- 0.011 over the wavelength range of 290-400 nm; the error limits correspond to 2sigma from the statistical analyses.The atmospheric lifetime of CF_3-CF_2C(O)CF(CF_3)_2 is estimated to be around 1 week,and the global warming potential of the compound is negligible.