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1.
Egyptian Journal of Chemistry. 1996; 39 (4): 401-9
em Inglês | IMEMR | ID: emr-40850

RESUMO

Catecholamine plays essential roles in the life chemistry, viz., the nature of biosynthesis, secretion and metabolism [1,2] It has direct action on sympathetic effective cells interacting with the receptor sites on the cell membrane, in cases where the sympathetic nerve has been cut or inhibited pharmacologically. On the other hand, noncatecholamines exert at least part of their effect by releasing physiological catecholamine from the postganglionic nerve fibers [3]. The choice of the extraction method and procedure of separation of catechol-and non-catecholamines depend on the nature of biological materials from which they have been separated and is suitable for direct bioassay or their colourimetric determination [4]. A number of extensive reviews have been appeared, covering aspects of environments of catecholamine in biological materials [3-6]. Many very stable complexes and chelates have been formed between mono, di-and polyhydric phenols with transition metals. Visible and ultravilot spectra of several transition metal complexes of pyrocatechol and tiron were studied. [7] Electronic absorption spectra of Co [III] and Cu [II] pyrocatechol complexes in solid state and in aqueous were also studied [8]. Reactions of 1,2 diphenol with iron [III] solutions were reported by Lumir et al[9] The main objective of the present study involves structure elucidation of the chelates formed between complexed iron and catecholamine. The combination between analytical and inorganic studies on the mixed ligand chelates formed enables understanding the nature of chemical reactions occurring


Assuntos
Catecolaminas
2.
Egyptian Journal of Chemistry. 1991; 34 (2): 121-9
em Inglês | IMEMR | ID: emr-107474

RESUMO

For mercuri-gravi-potentiometric microdetermination of phosphate, arsenate and sulfide, optimum conditions have been investigated for their precipitation with cations of Th [IV], Fe [III] and Hg [II] respectively. Excess EDTA was then added to react with unreacted cation and the remaining EDTA was finally back titrated with Hg [II] using silver amalgam and SCE combination. For microdetermination of these anions, the standard deviation, coefficient of variation, and percentage recovery were calculated indicating the high accuracy and reliability of the applied procedures. There is a significant correlation between suggested and standard procedures which confirmed by F and t tests


Assuntos
Fosfatos/análise , Arseniatos/análise , Sulfetos/análise
3.
Egyptian Journal of Chemistry. 1988; 31 (2): 233-39
em Inglês | IMEMR | ID: emr-107373

Assuntos
Fenóis/química
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