ENVR 88 |
| This study investigated the degradation pathway of the urine metabolite creatinine with immobilized titanium dioxide photocatalysts. The degradation of creatinine was studied at three different pH values (acidic, neutral and basic) in the absence of buffering solutions. The intermediates formed were identified by using an electrospray ionization mass spectrometer in both negative and positive modes. Two distinct mechanistic pathways were identified which govern the photodegradation of creatinine irrespective of the initial solution pH. The latter one only affected the selectivity between the two mechanisms. The oxidation steps of creatinine with hydroxyl radicals include demethylation, hydrogen abstraction, hydroxylation, oxidation and ring opening. At acidic pH, additional transformation steps of the two mechanisms were isolated. The intermediates detected in the positive ion mode contained at least one atom of nitrogen in their structure, explaining the observed low nitrogen mineralization of creatinine with TiO2 photocatalysis. The intermediates in the negative ion mode were low molecular weight organic acids that contained only carbon and hydrogen atoms. |
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The C. Ellen Gonter Environmental Chemistry Awards
1:30 PM-4:35 PM, Tuesday, August 21, 2007 Boston Park Plaza -- Beacon Hill Rm, Oral
Division of Environmental Chemistry |