OH radical reactivity of pesticides adsorbed on aerosol materials: First results of experiments with filter samples
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In: Ecotoxicology and Environmental Safety, Vol. 41, No. 1, 01.09.1998, p. 36-43.
Research output: Journal contributions › Journal articles › Research › peer-review
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TY - JOUR
T1 - OH radical reactivity of pesticides adsorbed on aerosol materials
T2 - First results of experiments with filter samples
AU - Palm, Wolf Ulrich
AU - Millet, Maurice
AU - Zetzsch, Cornelius
N1 - Copyright 1998 Academic Press.
PY - 1998/9/1
Y1 - 1998/9/1
N2 - Preliminary results of a new method to investigate the OH radical reactivity of semi-volatile organic compounds (e.g., pesticides) are presented. Terbuthylazine, simazine, sodium benzoate, and bromoxynil were adsorbed on highly disperse silicon dioxide powder as an unreactive carrier at a thickness well below one monolayer. The coated material was suspended in air as an aerosol, sampled on filters, and exposed in an 840-liter Duran chamber to OH radicals, produced by photolysis of hydrogen peroxide in the gas phase. Sunlamps on top of the chamber were used as cold light sources [T(aerosol) ≃ 25°C]. OH radical concentrations (105< c(OH) (cm-3) < 3 x 106) were monitored in the gas phase using a set of four hydrocarbons with well-known OH reactivities as reference compounds. The triazine terbuthylazine (k(OH)=1.1 x 10-11 cm3 s-1) was used as a reference compound in the filter samples. Simazine and isoproturon were found to react with a comparable OH rate constant with respect to terbuthylazine. Sodium benzoate reacts about a factor of 3 slower. Rapid degradation was observed for bromoxynil, explained mainly by photolysis. Besides the characterization and discussion of the experimental setup used, the rate constants obtained are discussed and compared with estimated values.
AB - Preliminary results of a new method to investigate the OH radical reactivity of semi-volatile organic compounds (e.g., pesticides) are presented. Terbuthylazine, simazine, sodium benzoate, and bromoxynil were adsorbed on highly disperse silicon dioxide powder as an unreactive carrier at a thickness well below one monolayer. The coated material was suspended in air as an aerosol, sampled on filters, and exposed in an 840-liter Duran chamber to OH radicals, produced by photolysis of hydrogen peroxide in the gas phase. Sunlamps on top of the chamber were used as cold light sources [T(aerosol) ≃ 25°C]. OH radical concentrations (105< c(OH) (cm-3) < 3 x 106) were monitored in the gas phase using a set of four hydrocarbons with well-known OH reactivities as reference compounds. The triazine terbuthylazine (k(OH)=1.1 x 10-11 cm3 s-1) was used as a reference compound in the filter samples. Simazine and isoproturon were found to react with a comparable OH rate constant with respect to terbuthylazine. Sodium benzoate reacts about a factor of 3 slower. Rapid degradation was observed for bromoxynil, explained mainly by photolysis. Besides the characterization and discussion of the experimental setup used, the rate constants obtained are discussed and compared with estimated values.
KW - Aerosol
KW - Bromoxynil
KW - Filter samples
KW - Isoproturon
KW - OH concentration
KW - OH rate constants
KW - Pesticides
KW - Simazine
KW - Sodium benzoate
KW - Terbuthylazine
KW - Chemistry
UR - http://www.scopus.com/inward/record.url?scp=0031696742&partnerID=8YFLogxK
U2 - 10.1006/eesa.1998.1664
DO - 10.1006/eesa.1998.1664
M3 - Journal articles
C2 - 9756687
AN - SCOPUS:0031696742
VL - 41
SP - 36
EP - 43
JO - Ecotoxicology and Environmental Safety
JF - Ecotoxicology and Environmental Safety
SN - 0147-6513
IS - 1
ER -