Sorption of organophosphorus and carbamate insecticides by soil

Felsot, Allan S.; Dahm, Paul A.

doi:10.1021/jf60223a013

Cited by 133 publications

(50 citation statements)

References 101 publications

(154 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The lin ear form of this equa tion is as fol lows: where x/m is the con cen tra tion of the ad sor bate per unit amount of ad sor bent (µg /g), Ce is the ad sor bate con cen tration in so lu tion af ter equil i bra tion (µg/mL), and K and 1/n are con stants rel a tive to the af fin ity of ad sor bent for ad sorbate and to the de gree of cur va ture of the iso therm, re spectively. The K value can be used to com pare sorp tion of dif fer ent her bi cides on var i ous soils at unit con cen tra tion 15 .…”

Section: Ad Sorp Tion Iso Thermsmentioning

confidence: 99%

“…The adsorption processes on soils has usually been determined by radio-tracer techniques (conventional method), us ing 14 C-labeled material diluted with pesticides and quan ti ta tive anal y sis by liq uid scin til la tion spectrom e try [13][14][15] .…”

Section: Introductionmentioning

confidence: 99%

“…Sorp tion of lindane var ied in dif fer ent Bra zil ian soils 12 . Felsot and Dahm 15 re lated that the vari able Freundlich iso therms for dif fer ent pes ti cides-soil sys tem in di cate that sorp tion is a com plex phe nom e non in volv ing dif fer ent types of ad sorption sites with dif fer ent sur face en er gies Ametryn (methlymercapto-triazine) was ad sorbed by all the soils more than all oth ers her bi cides in ves ti gated (Ta ble 3).…”

mentioning

confidence: 99%

See 2 more Smart Citations

HRGC study of sorption and desorption of atrazine, ametryn and metolachlor on Brazilian soils

Queiroz¹,

Lanças²

1997

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Os processos de adsorção e dessorção dos herbicidas ametrina, atrazina e metolaclor foram estudados em cinco so los brasileiros com diferentes conteúdos de matéria orgânica, utilizando-se cromatografia gasosa de alta resolução (HRGC). As linhas de regressão geradas apresentaram coeficiente de determinação > 0,964, indicando um bom ajuste dos da dos à equação de Freundlich. O equilíbrio de adsorção foi atingido em aproximadamente 6 h. Histerese foi observada nas isotermas de adsorção e dessorção. Correlações significativas foram encontradas en tre o coeficiente de adsorção, matéria orgânica e capacidade de troca de cátions. Não foram observadas correlações en tre o coeficiente de adsorção dos herbicidas (ametrina, atrazina e metolaclor) e solubilidade em água, pKa e massa mo lec u lar destes compostos, pois estes herbicidas não pertencem à mesma família química. Por este fato, as correlações en tre adsorção e propriedades dos herbicidas citadas acima foram estabelecidas somente en tre as triazinas. O coeficiente de adsorção das triazinas mostrou-se diretamente correlacionado com a solubilidade em água, pKa e massa mo lec u lar destes compostos nos solos avaliados.The sorp tion and desorption of her bi cides ametryn, atrazine and metolachlor were stud ied in five Bra zil ian soils with var i ous or ganic mat ter con tents us ing high res o lu tion gas chro matog ra phy (HRGC). The re gres sion lines gen er ated pre sented a co ef fi cient of de ter mi nation > 0.964, which in di cates a good fit of the data by the Freundlich equa tion. Sorp tion reached an ap par ent equi lib rium in the soils within ap prox i mately 6 h. Hys ter esis was ob served in both sorp tion and desorption iso therms. Sig nif i cant cor re la tions were found among sorp tion of herbi cides, or ganic mat ter, and cat ion-exchange ca pac ity. No re la tion ship was found be tween adsorp tion of the her bi cides (ametryn, atrazine, and metolachlor) and their wa ter sol u bil ity, pKa, and mo lec u lar mass, since these her bi cides do not be long to the same chem i cal fam ily. On account of this, the re la tion ship be tween sorp tion and her bi cide prop er ties cited above was es tablished only for s-triazines. The s-triazine ad sorp tion showed a di rect re la tion ship with wa ter sol u bil ity, pKa and mo lec u lar mass of these com pounds on the stud ied soils. Key words: ad sorp tion, desorption, her bi cides, soils In tro duc tionMetolachlor, atrazine and ametryn are widely used as selective pre-and post-emergence herbicides for weed con trol in sugar cane, cit rus fruit, soy beans and other eco nom i cally im por tant crops in Brazil. Res i dues of these her bi cides are fre quently found in en vi ron mental samples of soil and water due to their persistence and rel a tively high wa ter sol u bil ity 1,2 .In for ma tion on the ad sorp tion and desorption po ten tial of her bi cides is needed un der cer tain cir cum stances to assess move ment and per sis tence in a soil en vi ron ment. Better un der stand ing of these pro cesses wil...

show abstract

Section: Ad Sorp Tion Iso Thermsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

HRGC study of sorption and desorption of atrazine, ametryn and metolachlor on Brazilian soils

Queiroz¹,

Lanças²

1997

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…Hysteresis (= non-coincidence of adsorption and desorption isotherms), a phenomenon which has been observed in many pesticide adsorption studies including those with sterilized soils (ref. 30), is a further indication supporting this assumption. Chemical structures suitable for such binding would be ionic for basic substances such as phenols or anilines.…”

Section: Adsorption Sitesmentioning

confidence: 62%

“…30) in the context of adsorption-desorption studies, i.e. the adsorption to these sites is assumed to be reversible.…”

Section: Adsorption Sitesmentioning

confidence: 99%