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Multiple unknown degradants generated from the insect repellent DEET by photoinduced processes on TiO 2
Author(s) -
Medana Claudio,
Calza Paola,
Dal Bello Federica,
Raso Elena,
Minero Claudio,
Baiocchi Claudio
Publication year - 2011
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.1866
Subject(s) - deet , chemistry , oxidizing agent , photocatalysis , insect repellent , ecotoxicity , bioassay , alkyl , mineralization (soil science) , photochemistry , titanium dioxide , environmental chemistry , organic chemistry , chemical engineering , toxicology , toxicity , ecology , nitrogen , biology , genetics , engineering , catalysis
This paper deals with the photocatalytic transformation of N , N ‐diethyl‐ m ‐toluamide (DEET), one of the most widespread and efficient mosquito repellents, under simulated solar irradiation using titanium dioxide as the photocatalytic source of oxidizing species. The investigation involved monitoring of the DEET decomposition, the identification of intermediate compounds and the assessment of mineralization. High‐resolution mass spectrometry was employed to assess the evolution of the photocatalyzed process over time. Fifty‐one main species were identified after DEET transformation. Several isomeric species were formed and were characterized by analyzing MS and MS n spectra in full, and by comparison with parent molecule fragmentation pathways. In the DEET molecule, the initial transformation involved mono‐ and polyhydroxylation followed by oxidation of the alcohol groups, cleavage of the alkyl chains or ring opening. All these intermediates are easily degraded and DEET is completely mineralized after 4 h of irradiation. Microtox bioassay ( Vibrio fischeri ) was employed to evaluate the ecotoxicity of solutions treated by photocatalysis. Copyright © 2010 John Wiley & Sons, Ltd.