Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Añadir filtros








Intervalo de año
1.
Egyptian Journal of Chemistry. 1994; 37 (2): 145-156
en Inglés | IMEMR | ID: emr-32438

RESUMEN

Mono and binuclear cobalt [II], nickel [II] and copper [II] complexes containing quadridentate Schiff bases were prepared and characterized by elemental analysis, 1R, electronic and epr spectra. The complexes were subjected to TGA, conductance and electrical resistivity measurements. The observed resistivities of the complexes at different temperatures follow the order Co [II]

Asunto(s)
Naftalenos/síntesis química , Níquel , Cobalto , Cobre
2.
Alexandria Journal of Pharmaceutical Sciences. 1994; 8 (3): 191-194
en Inglés | IMEMR | ID: emr-31639

RESUMEN

A simple and rapid colorimetric method was described for the determination of isocarboxazid, iproniazid phosphate and phenylhydrazine hydrochloride. The method depended on the use of 2-iodoxybenzoic acid, as an oxidant in 50% w/v orthophosphoric acid to oxidize chlorpromazine HCl to chlorpromazine free radical, which absorbs at 530 mm. This red free radical was rapidly and quantitatively reduced by the investigated compounds to the colorless chlorpromazine. The decrease in absorbance was found to be directly proportional to the quantity of each compound studied, and this forms the basis for the quantitative estimation of micro-quantities of the investigated compounds


Asunto(s)
Colorimetría/métodos
3.
Mansoura Journal of Pharmaceutical Sciences. 1993; 9 (2): 178-90
en Inglés | IMEMR | ID: emr-28964

RESUMEN

Two procedures were adopted for determination of three pharmaceutical compounds containing thiol group; namely, D-penicillamine, N-acetylcysteine and captopril, by 2,6-dichlorophenol-indophenol [DCPIP]. In the first, the drugs are treated with a known and excessive volume of 1 x 10-3 M DCPIP and after 5 minutes the surplus is determined by titration with standard L-ascorbic acid. In the second, the drugs are titrated with 5 x 10-4 M solution of DCPIP with spectrophotometric end-point detection. The stoichiometry of the reaction is assumed and a reaction mechanism is suggested. The methods have been applied to the analysis of pharmaceutical preparation containing these drugs and the results obtained compared favorably with those from the pharmacopoeial methods. The methods are simple, accurate and precise


Asunto(s)
Compuestos de Sulfhidrilo/análisis
4.
Egyptian Journal of Chemistry. 1985; 28 (1): 53-56
en Inglés | IMEMR | ID: emr-5592

RESUMEN

Although atomic absorption spectrophotometry is commonly used for the direct determination of metals, the method is not suitable for the determination of organic substances. Various methods for the indirect determination of organic compounds are however used frequently 2-Hydroxynaphthoic acid has been determined indirectly through the selective extraction of the Ni [II] 2-Hydroxynaphthoate with nitrobenzene. Phthalic acid is extractable into methyl-isobutyl ketone as the ion pair formed between bis-[neocuproin] Cu [I] and the univalent anion of phthalic acid. A similar method has been employed for the determination of pentachlorophenol. Halonen and Aira were able to determine sugars by their depressive effect on the absorption of calcium. Sugar was also determined by atomic absorption Spectrophotometry after the reduction of CuSO[4] in a carbonate-tartarate solution. Berka et al. studied the oxidation of D-glucose by KMn0[4] in buffered and alkaline media. In the present investigation, and indirect method for the atomic absorption determination of glucose is developed based on the reaction with KMnO[4] under such conditions leading to the quantitative formation of MnO[2]. Both the unreacted KMnO[4] and formed MnO[2] are then determined by atomic absorption Spectrophotometry. Thus, the atomic absorption method for the determination of Mn is indirectly used for the determination of glucose


Asunto(s)
Espectrofotometría Atómica
5.
Egyptian Journal of Chemistry. 1985; 28 (3): 239-43
en Inglés | IMEMR | ID: emr-5620

RESUMEN

Organic solvents were used as media for atomic absorption determination of metals in order to increase the sensitivity of the method. Ivanov and Kozyrava used propanol in the determination of copper. Other applications were given for determination of lead and palladium. The atomic absorption method has been used for indirect determination of pharmaceutical compounds. Kanamycin sulphate is a member of aminogl ucosides which complexes with cupric ions, through its amino group. Amino nitrogen compounds were also determined using the same technique by allowing these compounds to react with dissociated copper phosphate in alkaline medium. In the present paper, the effect of a large variety of solvents, including alcohols and ketones, on the estimation of copper or kanamycin by atomic absorption spectrometry, investigated


Asunto(s)
Espectrofotometría Atómica , Kanamicina , Cobre
6.
Egyptian Journal of Chemistry. 1985; 28 (6): 447-56
en Inglés | IMEMR | ID: emr-5648

RESUMEN

The members of a new series of [M [HNAAA]]. x H2O are prepared, where, M = Ca[2+], Mn[2+], Fe[2+], Co[2+], Ni[3+],Cu[2+], Zn[2+], Mg[2+] and Sr[2+] and [HNAAA] is 2-hydroxy naphtnyl-1-azo Beta- acetylacetone [a dibasic tridentate ligand]. The complexes are-Subjected to elemental micro analysis and characterized by ir, electronic and [1] H nmr spectra, DTA and x-ray analysis. The stability constants of the complexes formed are determined by potentiometric techniques and discussed in relation to the ionic potentials


Asunto(s)
Quelantes
7.
Journal of Drug Research of Egypt. 1985; 16 (1-2): 93-98
en Inglés | IMEMR | ID: emr-5844

RESUMEN

An indirect atomic absorption method for the determination of lactose is developed. Heptavalent manganese is reduced in weakly acidic solutions by lactose to form insoluble MnO2. The concentration of lactose in the solution is determined from a calibration curve prepared from measurements made on known amounts of lactose. In the meantime the quantity of MnO2 formed is proportional to the concentration of lactose added and the formed Mn[2+] ions are determined by atomic absorption spectrophotometry


Asunto(s)
Espectrofotometría Atómica
8.
Egyptian Journal of Pharmaceutical Sciences. 1984; 25 (1-4): 213-8
en Inglés | IMEMR | ID: emr-4234
9.
Egyptian Journal of Pharmaceutical Sciences. 1984; 25 (1-4): 219-25
en Inglés | IMEMR | ID: emr-4235
11.
Journal of Drug Research of Egypt. 1984; 15 (1-2): 7-11
en Inglés | IMEMR | ID: emr-4508

RESUMEN

The effect of mineral and organic acids on atomic absorption determination of manganese is studied. The results show that the atomic absorption of manganese decreased in presence of these acids. The results are discussed in the light of complex formation, density and viscosity of the solution


Asunto(s)
Espectrofotometría Atómica , Ácidos
12.
Journal of Drug Research of Egypt. 1984; 15 (1-2): 144-147
en Inglés | IMEMR | ID: emr-4526

RESUMEN

An indirect method has been developed for the determination of uranium by atomic absorption spectrophotometry using an air-acetylene flame. Use is of the reduction of iron [III] by uranium [IV] followed by complex formation of the iron [II] ions so produced with 1, 10-phenanthroline and finally the determination of iron in this complex by atomic absorption spectrophotometry


Asunto(s)
Espectrofotometría Atómica
13.
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA