Rate of Detoxification of 4‐amino‐3,5,6‐trichloropicolinic Acid in Soil

Hamaker, John W.; Youngson, C. R.; Goring, C. A. I.

doi:10.1111/j.1365-3180.1968.tb01400.x

Cited by 37 publications

(15 citation statements)

References 5 publications

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“…However, Youngson et al (1967) also studied the degradation of picloram and confirmed first-order kinetics, but did not find a lag phase. In a later paper by the same group (Hamaker, Youngson & Goring, 1968) it was found that half-order and Michaelis-Mentcn kinetics most satisfactorily described the degradation of picloram in soil.…”

Section: Introductionmentioning

confidence: 96%

The Degradation of Triazine and Uracil Herbicides in Soil*

et al. 1970

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Summary. The rates of degradation of three triazine and two uracil herbicides were followed at 13·2 and 31·2°C in one soil. Soil was treated with 8 ppm of 2‐chloro‐4‐ethyl‐amino‐6‐isopropylamino‐1,3,5‐triazine (atrazine), 2‐chloro‐4,6‐bisethylamino‐1,3,5‐triazine (simazine), 2‐mcthylthio‐4‐ethylamino‐6‐isopropylamino‐1,3,5‐triazine (ametryne), 3‐sec‐butyl‐5‐bromo‐6‐methyluracil (bromacil) and 3‐tert‐butyl‐5‐chloro‐6‐methyluracil (terbacil) and monthly samples analysed chemically to determine the amounts remaining. Evaluation of the rate constant at two temperatures permitted calculation of the energy of activation from the Arrhenius equation. It was determined to a first approximation that soil degradation followed a first order rate law with no lag period and that the rate could be related to molecular structure. The energies of activation in kcals/mole were: atrazine 10‐8, simazine 9‐2, ametryne 6‐1, bromacil 3‐0, and terbacil 6‐1. These values suggest breakage of the common carbon‐chlorine bond in atrazine and simazine but breakage of a different bond in ametryne. Examination of bond energies and known mechanisms of breakdown for triazines supported the hypothesis of breakage of the bond at the two position. The data on decomposition of the uracils indicate that the carbon‐halogen bond was broken in each molecule. Dégradation des triazines et des uraciles herbicides dans le sol Résumé. Les taux de dégradation de trois triazines et de deux uraciles herbicides ont été observés α 13,2 et 31,2° C dans un sol. Ce sol a été traitéà la concentration de 8 ppm avec la 2‐chloro‐4‐éthyIainino‐6‐isopropylamino‐1,3,5‐triazine (atrazine), la 2‐chloro‐4,6‐biséthylamino‐l,3,5‐triazine (simazine), la 2 méthylthio‐4‐éthylamino‐6‐isopropylamino‐1,3,5‐triazine (amétryne), le 3‐sec‐butyl‐5‐bromo‐6‐méthyluracile (bromacil) et le 3‐tert‐butyl‐5‐chloro‐6‐méthyluracile (terbacil). Des échunlillons ont été analysés chimiquement tous les mois pour déterminer les résidus. L'évaluation du taux constant à deux températures a permis le calcul de l'energie d'activation d'aprés l'équation d'Arrhenius. Selon une premiére approximation, la dégradation a suivi une loi de taux de premier ordre sans période de retard et le taux peut être reliéà la structure moléculaire. Les énergies d'activation en kcals/mole furent: atrazine 10,8, simazine 9,2, amétryne 6,1, bromacil 3,0 et terbacil 6,1. Ces valeurs suggérent une rupture d'une liaison carbone‐chlore dans I'atrazine et la simazine mais la rupture d'une liaison différente dans l'amétryne. L'examen des énergies de liaison et des mécanismes connus de dégradation pour les triazines amène à formuler l'hypothése de la rupture d'une liaison en position deux. Les résultats relatifs aux uraciles indiquent tjue la liaison carbone‐halogéne a été rompue dans chaque molécule. Der Abbau von Triazin‐ und Uracilherbiziden im Boden Zusammenfassung. Die Abbaurate von 3 Triazin‐ und 2 Uracilherbiziden im Boden wurde bei 13,2 und 3l,2°C untersucht. Aus dem mit 8 ppm 2‐Chlor‐4‐athylamino‐6‐isopropylamino‐1,3,5‐tria...

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Section: Introductionmentioning

confidence: 96%

The Degradation of Triazine and Uracil Herbicides in Soil*

et al. 1970

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“…However, Hamaker el a1. 3 showed that picloram degradation was better described by a hyperbolic expression. Hance and M~K o n e ,~ found that the decomposition of atrazine, linuron and picloram could not be described very well by the first-order rate law, nor by zero, half or Michaelis-Menten kinetics.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of linuron and metribuzin degradation in soil

Kempson-Jones

Hance

1979

Pestic. Sci.

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The disappearance of linuron and metribuzin was studied during laboratory incubation of soil samples which had been taken from several depths at three sites, and treated with the pesticides. Temperature and water content of the soils were varied. There was a tendency for the rate of loss to be slower in soil taken from deeper horizons than in surface soil but the differences were not large. In only ten out of forty experiments did the value 1 for the apparent order of reaction fall within 95% confidence limits. In the remaining experiments the apparent reaction order was greater than 1 with eight values higher than 4. For one soil, the reaction order for linuron was markedly lower for incubation at 22°C compared with incubations at 10°C. The results could be explained on the basis that the systems were complex, involving consecutive or competing reactions. An alternative possibility is that the apparent complexities were artifacts brought about by the inherent limitations of the laboratory incubation system.

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“…A great deal of effort has gone into the preparation of kinetic curves for degradation of pesticides presently in use. Imperical data are generally fitted to some sort of decay curve, such as the power rate model (Hamaker 1972), the Monod model (Monod 1949), the logistic curve (Odum 1971), Michaelis Menten kinetics (Alexander and Scow 1989;Hance and McKone 1971;Hamaker et al 1968;Somas 1982), and multiple compartment models (Alexander and Scow 1989;Hamaker and Goring 1976).…”

Section: Predicting Environmental Fate Of Pesticidesmentioning

confidence: 99%

Biodegradation

1991

Springer Series in Applied Biology

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Rate of Detoxification of 4‐amino‐3,5,6‐trichloropicolinic Acid in Soil

Cited by 37 publications

References 5 publications

The Degradation of Triazine and Uracil Herbicides in Soil*

The Degradation of Triazine and Uracil Herbicides in Soil*

Kinetics of linuron and metribuzin degradation in soil

Biodegradation

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