PMID- 21060930
OWN - NLM
STAT- MEDLINE
DCOM- 20110331
LR  - 20131121
IS  - 1463-9084 (Electronic)
IS  - 1463-9076 (Linking)
VI  - 13
IP  - 2
DP  - 2011 Jan 14
TI  - Heterogeneous oxidation of the insecticide cypermethrin as thin film and airborne 
      particles by hydroxyl radicals and ozone.
PG  - 506-17
LID - 10.1039/c0cp00931h [doi]
AB  - Evaluation of pesticides' fate in the atmosphere is important in terms of 
      environmental effects on non-target areas and risk assessments analysis. This 
      evaluation is usually done in the laboratory using analytical grade materials and 
      is then extrapolated to more realistic conditions. To assess the effect of the 
      pesticide purity level (i.e. analytical vs. technical) and state (i.e. sorbed 
      film vs. airborne particles), we have investigated the oxidation rates and 
      products of technical grade cypermethrin as thin film and in its airborne form, 
      and compared it with our former results for analytical grade material. Technical 
      grade thin film kinetics for both ozone and OH radicals revealed reaction rates 
      similar to the analytical material, implying that for these processes, the 
      analytical grade can be used as a good proxy. Oxidation products, however, were 
      slightly different with two additional condensed phase products: formanilide, 
      N-phenyl and 2-biphenyl carboxylic acid, which were seen with the technical grade 
      material only. OH experiments revealed spectral changes that suggest the 
      immediate formation of surface products containing OH functionalities. For the 
      ozonolysis studies of airborne material, a novel set-up was used, which included 
      a long-path FTIR cell in conjugation with a Scanning Mobility Particle Sizer 
      (SMPS) system. This set-up allowed monitoring of real-time reaction kinetics and 
      product formation (gas and condensed phases) together with aerosol size 
      distribution measurements. Similar condensed phase products were observed for 
      airborne and thin film technical grade cypermethrin after ozonolysis. 
      Additionally, CO, CO(2) and possibly acetaldehyde were identified as gaseous 
      oxidation products in the aerosols experiments only. A kinetic model fitted to 
      our experimental system enabled the identification of both primary and secondary 
      products as well as extraction of a formation rate constant. Kinetic calculations 
      (based on gaseous products formation rate) have revealed values similar to that 
      of the thin film experiments. Interestingly, heterogeneous oxidation of 
      cypermethrin was also found to generate ultra fine secondary organic aerosols. 
      Again, no significant difference was observed between analytical and technical 
      grade materials. However, particle size distribution was much broader when films 
      were exposed to OH and ozone than to ozone alone.
FAU - Segal-Rosenheimer, M
AU  - Segal-Rosenheimer M
AD  - Faculty of Civil and Environmental Engineering, Technion-Israel Institute of 
      Technology, Technion City, 32000, Haifa, Israel. segalm@tx.technion.ac.il
FAU - Linker, R
AU  - Linker R
FAU - Dubowski, Y
AU  - Dubowski Y
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20101108
PL  - England
TA  - Phys Chem Chem Phys
JT  - Physical chemistry chemical physics : PCCP
JID - 100888160
RN  - 0 (Aerosols)
RN  - 0 (Insecticides)
RN  - 0 (Pyrethrins)
RN  - 1TR49121NP (cypermethrin)
RN  - 3352-57-6 (Hydroxyl Radical)
RN  - 66H7ZZK23N (Ozone)
SB  - IM
MH  - Aerosols/chemistry
MH  - Gas Chromatography-Mass Spectrometry
MH  - Hydroxyl Radical/*chemistry
MH  - Insecticides/*chemistry
MH  - Kinetics
MH  - Oxidation-Reduction
MH  - Ozone/*chemistry
MH  - Pyrethrins/*chemistry
MH  - Spectroscopy, Fourier Transform Infrared
EDAT- 2010/11/10 06:00
MHDA- 2011/04/01 06:00
CRDT- 2010/11/10 06:00
PHST- 2010/11/10 06:00 [entrez]
PHST- 2010/11/10 06:00 [pubmed]
PHST- 2011/04/01 06:00 [medline]
AID - 10.1039/c0cp00931h [doi]
PST - ppublish
SO  - Phys Chem Chem Phys. 2011 Jan 14;13(2):506-17. doi: 10.1039/c0cp00931h. Epub 2010 
      Nov 8.