Data/hora: 11/06/2024 23:23:08

Biblioteca(s): | Embrapa Instrumentação.
Data corrente: | 07/03/2001
Data da última atualização: | 16/04/2007
Autoria: | ASSIS, O. B. G.; FLORES, A. M.; CAMPANA FILHO, S. P.
Afiliação: | Embrapa Instrumentacao Agropecuaria; USP-IQSC.
Título: | A liquid-cromatography evaluation of atrazine sorption by CMC.
Ano de publicação: | 2000
Fonte/Imprenta: | In: SIMPOSIUM LATINOAMERICANO DE POLIMEROS-SLAP 2000, 7.; CONGRESO IBEROAMERICANO DE POLIMEROS, 5.; SIMPOSIUM LATINOAMERICANO DE QUITINA Y QUITOSANA, 1., 2000, La Habana. Livro de resumenes=Livro de resumos=Book of abstracts... La Habana: Sociedad Cubana de Quimica,2000.
Páginas: | p. 286.
Idioma: | Inglês
Notas: | Ref. 7-C8.
Conteúdo: | Cellulose and its derivatives have been widely used in a broad range of applications from biomedical, food and textiles to environmental fields. In particular, the carboxymethylcellulose (CMC) has been attracting attention due to its technological uses. CMC is a strong film former, adhesive and agglutinating material, food stabilizer, as well as having excellent liquid absorbent proprieties with potential to be used in wastewater purifying systems. CMC degrades completely which is a characteristic of interest due to the possibility of interacting with contaminates, be removed and reallocated in a safety site. In this work, the degree os sorption of the herbicide atrazine (ATZ) by CMC was evaluted via HPLC (High performance liquid-chromatography). The experimental procedure consisted in identifying the ultra-violet ATZ` absorption band followed by quantitative valuation of ATZ-CMC interaction in function of time. Atrazine (2-chloro-4-ethylamino-6isopropylamino-1,3,5-triazine) (99% purity) was prepared in 30mgLE-1 concentration in deionised water and methanol (1% v/v), and kept in solution with CMC aqueous batch (240gmolE-1 active sites) in moderated stirring for 48 hours. Two typical absorpition peaks, at 260 and 223nm characterize the herbicide U.V. spectrum. For chromatographic analysis was used a Shimadzu Chromatographer CBM-10A system with automatic injection sample volume. The optimum move phase composition was MeOH:H2O (70:30) in 1 mL/min flux. The analyses were carried out in a proportion of 20:1 CMC-ATZ. Concentrations of 12 and 1.5ppm ATZ at 30min. and 48 hours CMC interaction were analysed. The choice of these interaction intervals is based on the previous works carried out by DPP (differential pulse polarography). From the chromatograms , it is seen that the higer intensity peak appears at approximately 4.6 minutes in 223nm. By numerical integration the sorption of ATZ by CMC, related to the initial and final period interaction, showed a reduction of 6.5% of ATZ in 12ppm solution and 3.1% in !.5ppm solution.This wavelength corresponds to the absorbance band of ATZ. The other resulting peaks are related to impurities of the commercial ATZ composition. Although numerically short, these values are significant concerning the low interactivity presented by ATZ molecules. This difference is understood as owing to the CMC-ATZ proportion, i,e., since the volume relation keeps the same, the 1.5ppm, in 20:1 solution is not efficient as 70:1, where in the first the molecules present a higer degree of liberty reducing their interactivity
Palavras-Chave: | ATZ; CMC; Cromatografia liquida; High performance liquid-chromatography; HLPC; Instrumentacao; Tecnica; Ultravioleta.
Thesagro: | Atrazina; Carboximetilcelulose.
Thesaurus Nal: | chromatography.
Categoria do assunto: | --
Registro original: | Embrapa Instrumentação (CNPDIA)
Exemplares: | CNPDIA - (5853-1) - UPC - SP - -- - PROCI-00.0189 -  - 2000.0189 - DIS