Assuntos
Água Doce/análise , Inseticidas/farmacologia , Limoninas , Triterpenos/farmacologia , Poluentes Químicos da Água/análise , Zooplâncton/efeitos dos fármacos , Animais , Monitoramento Ambiental/métodos , Sedimentos Geológicos/análise , Inseticidas/metabolismo , Magnoliopsida/efeitos dos fármacos , Triterpenos/metabolismoRESUMO
Lethal and sublethal effects of dietary triclopyr butoxyethyl ester (TBEE) on zebra finches (Poephila guttata Gould) were determined in laboratory experiments conducted between 8 January and 1 May 1991. The 8-day median lethal dietary concentration, LC50 (95% confidence interval), of TBEE to zebra finches was 1,923 (1,627 to 2,277) mg/kg. In the sublethal effects experiment, when birds were exposed to 500 mg/kg TBEE in the diet for 29 days, food consumption and body weight were significantly depressed (P < 0.05). Similar prolonged exposures to 50 and 150 mg/kg TBEE in the diet had no significant effect on food consumption or body weight (P > 0.05). Perch-hopping activity was depressed relative to controls in the 500 mg/kg group, and elevated in the 150 mg/kg group, but neither of these differences was significantly (P > 0.05). Disappearance of TBEE residues from treated seeds over the 29 day experimental period followed an exponential decay model, with half-lives in the order of 15 to 18 days. On the basis of our observation that TBEE had no significant adverse effects at a concentration greater than the maximum expected environmental concentration, we propose that forestry applications of triclopyr at registered dosage rates pose little risk to wild songbirds.
Assuntos
Ração Animal/toxicidade , Doenças das Aves/induzido quimicamente , Contaminação de Alimentos , Glicolatos/toxicidade , Herbicidas/toxicidade , Análise de Variância , Animais , Comportamento Animal/efeitos dos fármacos , Aves , Peso Corporal/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Masculino , Resíduos de Praguicidas/toxicidade , Distribuição Aleatória , Análise de Regressão , SementesRESUMO
A liquid chromatographic method for determining glyphosate (GLYPH) and its major metabolite aminomethylphosphonic acid (AMPA) in various environmental substrates is described. Ion-exchange column chromatography is coupled with post-column ninhydrin derivatization and absorbance detection at 570 nm. Use of a valve-switching technique allowed quantitation of both analytes in a single chromatographic run and eliminated slow-eluting, coextracted interferences. The method was successfully used to quantitate GLYPH and AMPA in organic and mineral soils, stream sediments, and foliage of 2 hardwood brush species. Mean recovery efficiencies for GLYPH as determined from fortified blank field samples were as follows: bottom sediment 84%, suspended sediment 66%, organic soils 79%, mineral soils 73%, alder leaf litter 81%, salmonberry leaf litter 84%, and artificial deposit collectors 87%. Precision for GLYPH determination was good with less than 14% coefficient of variation on mean recovery for all substrates. Limits of detection were lowest for sediments (0.01 microgram/g dry mass) and highest for foliage substrates (0.10 microgram/g dry mass). Using this system, 6 samples/person/day were routinely analyzed.