Now showing items 31-36 of 36
Pre-concentration of Cd(II), Cr(III), Cu(II) and Ni(II) on a column packed with free carboxymethylcellulose (CMCH)
(Journal of the Brazilian Chemical Society, 1997-12-01) [Artigo]
Carboxymethylcellulose packed in to a glass column was used to pre-concentrate metallic cations from aqueous solutions. The pre-concentrated metal cations are directly eluted from the column using 5.0 mL of 1.0 mol L -1 ...
Determination of metal ions in natural waters by flame-AAS after preconcentration on a 5-amino-1,3,4-thiadiazole-2-thiol modified silica gel.
(Analytical Letters, 1999-01-01) [Artigo]
5-amino-1,3,4-thiadiazole-2-thiol groups attached on a silica gel surface have been used for adsorption of Cd(II), Co(II), Cu(II), Fe(III), Ni(II), Pb(II) and Zn(II) from aqueous solutions. The adsorption capacities for ...
Caracterização e propriedades catalíticas da zeolita HZSM5 modificada com nióbio
(Química Nova, 1997-02-01) [Artigo]
HZSM5 zeolite was modified by exchanging proton by niobium (V). Several samples were obtained with various degrees of exchange. Pore volumes and acidity were measured to characterize these exchanged zeolites. Catalytic ...
Flame AAS determination of metal ions in fuel ethanol after preconcentration on acid carboxymethylcellulose (CMCH)
(Quimica Analitica, 1999-01-01) [Artigo]
This paper describes the preparation of acid carboxymethylcellulose (CMCH), and the results of a study on the adsorption and preconcentration (using batch and flow-through column methods) of Cd(II), Cu(II), Cr(III), Fe(III), ...
The electrochemical cleavage of the nitrobenzoyl group from butyl nitrobenzoates in N,N-dimethylformamide
(Journal of Electroanalytical Chemistry, 1996-10-30) [Artigo]
The applicability of the nitrobenzoyl group [NO2C6H4CO-] to protecting the functional hydroxyl group was investigated through study of the electrochemical behaviour of the butyl 4-, 3- and 2-nitrobenzoate compounds. These ...
NICKEL CHLORIDE EFFECTS ON ERYTHROCYTE GENERATION OF SUPEROXIDE RADICAL
(Brazilian Journal of Medical and Biological Research, 1990-01-01) [Artigo]