Comparison of concentrations and stereoisomer ratios of mecoprop, dichlorprop and metolachlor in Ontario streams, 2006-2007 vs. 2003-2004.
Environ Pollut
; 158(5): 1842-9, 2010 May.
Article
em En
| MEDLINE
| ID: mdl-19962221
ABSTRACT
Mecoprop, dichlorprop and metolachlor concentrations and enantiomer signatures were determined in Ontario streams in 2006-2007 and compared to results from 2003 to 2004. Median concentrations of dichlorprop and metolachlor were not significantly different between the two campaigns, but mecoprop was higher in 2006-2007. Concentrations of mecoprop and dichlorprop in Lake Ontario surface water were 1-2 orders of magnitude lower than stream averages. Enantiomer fractions (EFs) > 0.5 of mecoprop in high-concentration stream water samples during 2006-2007 were related to replacement of racemic mecoprop by single (+) enantiomer mecoprop-P after 2004. EFs <0.5 in low-concentration samples suggested enantioselective degradation and/or interconversion. Metolachlor profiles were expressed as SF, the fraction of herbicidally active/(active + inactive) stereoisomers. Samples with higher concentrations of metolachlor had SFs similar to S-metolachlor which is enriched in the active stereoisomers. Low concentrations were associated with lower and more variable SFs, suggesting mixed input of racemic and S-metolachlor or stereoselective degradation.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
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Ácido 2-Metil-4-clorofenoxiacético
/
Rios
/
Ácido 2,4-Diclorofenoxiacético
/
Herbicidas
/
Acetamidas
País/Região como assunto:
America do norte
Idioma:
En
Revista:
Environ Pollut
Assunto da revista:
SAUDE AMBIENTAL
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Canadá