Data/hora: 16/06/2024 11:05:19

Biblioteca(s): 	Embrapa Instrumentação.	
Data corrente: 	22/12/1999	
Data da última atualização: 	06/11/2007	
Autoria: 	VAZ, C. M. P.; MASSAROPI, M. R. C.; MACHADO, S. A. S.; MAZO, L. H.; AVACA, L. A.; CRESTANA, S.	
Afiliação: 	EMBRAPA-CNPDIA; USP-IQSC.	
Título: 	Adsorption isotherms of atrazine and 2,4-D in soils using differential pulse polarography.	
Ano de publicação: 	1996	
Fonte/Imprenta: 	In: IUPAC GARP WORKSHOP PN PESTICIDES: USES AND ENVIRONMENTAL SAFETY IN LATIN AMERICA, Oct. 1996, Sao Paulo, SP. Book of abstracts... Sao Paulo: Sociedade Brasileira de Quimica, 1996.	
Páginas: 	p. 65. Ref.P-03.	
Idioma: 	Inglês	
Conteúdo: 	Polarographic techniques have been used to determine concentrations of many pesticides in different samples like natural waters, soils, vegetables and others. We identified in the literature over 40 active ingredients of pesticides analyzed or studied in some extend by means of polarographic techniques. In comparison with chromatography, the main technique used to analyze pesticides, the polarographic procedures are faster, cheaper and easier to be carried out. Moreover, they can be sucessfully employed for the analysis of colored materials or samples containing dispersed solid particles. The disadvantages are, in many cases, related to lower selectivity and sensitivity. The subject of this owrk is to use differential pulse polarography to determine atrazine and 2,4-D herbicide concentrations in soil samples for adsorption studies. Measurements were carried out in a model 384B Polarographic Analyzer from EG&G PARC, connected with a model 303A EG&G PARC dropping mercury electrode. Adsorption isotherms of atrazine and 2,4-D were obtained on some Brazilian soils using bath equilibrium experiments. The soil samples containing pesticide in concentration varying between 0.1 and 20 microgr.ml-1 were agitated during 24 hours and centrifuged to separate soil solution from the soil material. Concentrations of atrazine were determined directly in these solutions after adjusting pH to 2.3. The herbicide 2,4-D is not electroactive on mercury and has to undergo a nitration procedure to become electroactive...	
Palavras-Chave: 	Agricultural instrumentation; Differential pulse polarography; DPP; Herbicidas; Instrumentacao agropecuaria; Isotermos; Isotherms.	
Thesagro: 	Adsorção; Atrazina; Solo.	
Thesaurus Nal: 	adsorption; atrazine; herbicides; soil.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Instrumentação (CNPDIA)	
Exemplares: 	CNPDIA - (5605-1) - UPC - SP - -- - PROCI-96.00198 -  - 1996.00198 - DIS