Further Studies on Degradation of the Pyrethroid Insecticide Fenvalerate in Soils

Mikami, Nobuyoshi; Sakata, Shinoi; Yamada, Hirohiko; Miyamoto, Junshi

doi:10.1584/jpestics.9.697

Cited by 15 publications

(18 citation statements)

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“…The identified major photoproducts in water and on soil were also detected among the metabolites of PI in plants, 5-7) soils, [8][9][10][11] ratsl2-14) and mice, 15, 16) Major photoproducts such as P6 and P14 were biodegradable in nature and less toxic than PI to killifish with 48 hr LC50 values of more than 10 ppm, 34) …”

Section: Discussionmentioning

confidence: 92%

“…1) Cypermethrin is two to three times more active toward houseflies than permethrin, 1-3) and the (1 RS)-cis-isomers are more active than the corresponding (1RS)-trans-isomers by a factor of two. 4) From the viewpoint of environmental safety, studies on metabolism of P1 in plants, 5-7) soils, [8][9][10][11] rats12-14) and mice15, 18) have already been performed. This paper deals with photodegradation of the (1R, cis, czRS)-and (1R, trans, zRS)-isomers in water and soil surface in natural sunlight, using six kinds of 14C-labeled preparations.…”

Section: Introductionmentioning

confidence: 99%

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Photodegradation of the Pyrethroid Insecticide Cypermethrin in Water and on Soil Surface

et al. 1985

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Photodegradation of (1R, cis, ceRS)-and (1R, traps, ceRS)-isomers of Cypermethrin [(RS)-a-cyano-3-phenoxybenzyl(1RS)-cis, traps-3-(2, 2-dichlorovinyl)-2, 2-dimethylcyclopropanecarboxylate] in water and on soil surface was studied, using 14C preparations labeled separately at the cyclopropyl C-1, cyano or benzyl ring. The cis-isomer was photodecomposed 1. 4-1. 7 times faster in sunlight than the traps-isomer in water. The half-life of the cis-isomer was 2. 3-2. 6 days in distilled water and 1 ppm humic acid aqueous solution, and 0. 6-0. 7 day in natural river and sea water, and <0. 5 day in 2% aqueous acetone. A triplet photosensitizer acetone together with the naturally occurring substances in river and sea water enhanced the photodegradation of both isomers. On three kinds of soil surface, both isomers were rapidly photodegraded with the initial half-life of 0. 6-1. 9 days. The photoreactions involved were: 1R/1S and cis/trans isomerization of the cyclopropane ring, cleavage of the ester or diphenyl ether linkage, oxidation of the CHO group to the COOH group, hydration of the CN group to the CONH2 group, hydrolysis of the CONH2 group to the COOH group, oxidative cleavage of the halogenated side chain, dehalogenation, intramolecular cyclization to form y-or 8-lactone, and photomineralization of the cyclopropyl C-1, cyano and benzyl ring to 14CO2.

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Section: Discussionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Photodegradation of the Pyrethroid Insecticide Cypermethrin in Water and on Soil Surface

et al. 1985

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“…The isolated polar metabolite could be confirmed to be PG by two-dimensional TLC co-chromatography. CPG exhibited the maximum formation of 4.6-8.9% at days 3-7 but decreased with PG formation (maximum, 4.1-14.6% at days [7][8][9][10][11][12][13][14]. None of these compounds exceeded 5.3% of the applied 14 C at day 60 and therefore, all of these degradates were considered to be finally stepwise degraded to carbon dioxide or bound to soils.…”

Section: Degradation Products Of Ipmentioning

confidence: 99%

“…1) The metabolic profiles of synthetic pyrethroids such as phenothrin, 2) permethrin, 3) cypermethrin 4,5) and fenvalerate, 6,7) have been extensively investigated in aerobic soils and their variable degradability with half-lives of 1 day-16 weeks was found to significantly depend on either soil characteristics or microbial activity. 8,9) Their main degradation pathways are the hydrolytic cleavage of an ester linkage, stepwise hydration of a cyano group, cleavage of a diphenyl ether bond and ring hydroxylation of a phenoxybenzyl moiety.…”

Section: Introductionmentioning

confidence: 99%

Aerobic metabolism and adsorption of pyrethroid insecticide imiprothrin in soil

2006

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Imiprothrin, a unique type of pyrethroid having an imidazolidinyl ring in its alcohol moiety, was rapidly degraded in two aerobic U.S. soils. The half-lives of biologically active trans isomer were estimated by assuming the first-order kinetics to be 1.6-2.5 days, shorter than those of the cis isomer (3.3-12.5 days). The primary metabolic pathway was ester cleavage followed by instantaneous elimination of a hydroxylmethyl group from the alcohol moiety to form PGH (1-propargylimidazolidine-2,4-dione). The opening of the imidazolidinyl ring with subsequent release of the carbamoyl group resulted in the formation of PG (N-propargylglycine). The soil adsorption coefficients (K oc ) of the trans isomer, the main component of imiprothrin (80%), to the two soils were determined to be 376 and 428 (ml/g o.c.) by the batch equilibrium method and these lower values as compared with other pyrethroids were likely to stem from the hydrophilic character of the alcohol moiety. Based on the metabolic half-lives and K oc values, the groundwater concentration of imiprothrin was calculated to be 0.039 mg/L by using the screening simulation model SCI-GROW known to give a conservative groundwater concentration. This significant lower concentration clearly indicates that imiprothrin is most unlikely to contaminate the groundwater, mainly due to its rapid degradation in soil.

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“…Such reactions have been reported with permethrin,16,17) cypermethrin14,18) and fenvalerate. 13,19) In common with other synthetic pyrethroids,20) I is hardly eluted from soils with water18) because of its extremely quite low watersolubility and rapid adsorption to soil particles. Therefore, it is reasonable to assume that in agricultural fields, I is almost localized in application sites without moving toward a lower soil layer with water and is readily decomposed mainly by microbial actions to yield CO2 in the ultimate.…”

Section: Discussionmentioning

confidence: 99%

Degradation and Leaching Behavior of the Pyrethroid Insecticide Fenpropathrin in Soils

et al. 1990

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Further Studies on Degradation of the Pyrethroid Insecticide Fenvalerate in Soils

Cited by 15 publications

References 0 publications

Photodegradation of the Pyrethroid Insecticide Cypermethrin in Water and on Soil Surface

Photodegradation of the Pyrethroid Insecticide Cypermethrin in Water and on Soil Surface

Aerobic metabolism and adsorption of pyrethroid insecticide imiprothrin in soil

Degradation and Leaching Behavior of the Pyrethroid Insecticide Fenpropathrin in Soils

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