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1.
We report a simple TLC densitometric method for the quantification of hecogenin from the leaves of Agave americana using HPTLC. The method was validated for precision, repeatability and accuracy. The method was found to be precise with
RSD of 0.78 (intraday) and 0.82 (interday) for different concentrations of hecogenin. Instrumental precision was 0.42 (% RSD)
for hecogenin. The content of hecogenin in different samples was estimated by the proposed method and was found to be in the
range of 0.05−0.14% w/w in the samples analysed. Accuracy of the method was checked by conducting recovery study at three different levels for hecogenin
and the average percentage recovery was 98.98%, 101.92% and 103.33%, respectively. The TLC densitometric method developed
for the quantification of hecogenin was found to be simple, precise, specific, sensitive, accurate and can be used in routine
quality control.
Revised: 7 and 25 April 2006 相似文献
2.
Vishwakarma Santosh L. Bagul Milind S. Rajani M. Goyal Ramesh K. 《平面色谱法杂志一现代薄层色谱法》2004,17(2):128-131
JPC – Journal of Planar Chromatography – Modern TLC - Swertiamarin is a secoiridoid glucoside present in members of the Gentianaceae family, including Swertia chirata (Wall) Clarke, S.... 相似文献
3.
4.
Rajani K. Samal R. R. Das M. C. Nayak G. V. Suryanarayana G. Panda D. P. Das 《Journal of polymer science. Part A, Polymer chemistry》1981,19(11):2751-2758
The kinetics of polymerization of acrylonitrile initiated by KHSO5 and catalyzed by Ag(I) have been investigated in an aqueous medium over the temperature range of 35–50°C. The rates of polymerization Rp have been calculated and studied with respect to monomer and initiator. The catalytic activity of various metal ions on the initiator has been determined from a comparison of Rp values. The effects of monomer, catalyst, neutral salts, various amines, and inhibitor (hydroquinone) on the initial rate as well as maximum conversion have been studied. From the kinetics results a suitable reaction scheme has been proposed. 相似文献
5.
Rajani K. Samal Padma L. Nayak Mohan C. Nayak Akshaya K. Dhal 《Journal of polymer science. Part A, Polymer chemistry》1980,18(6):2001-2010
Kinetics of the polymerization of acrylonitrile has been investigated in aqueous sulfuric acid in a temperature range of 25–45°C. The rate of polymerization (Rp) and the rate of managanic ion disappearance, etc., have been measured. The effect of the various additives, such as water-miscible organic solvents, neutral electrolytes, complexing agents, and surfactants, on the rate has been thoroughly studied. A mechanism that involves the initial complex formation between the thiol form of the thioamide and Mn3+, whose decomposition yields the initiating free radical with the polymer chain terminated by mutual combination of growing radicals, has been suggested. 相似文献
6.
Rajani K. Samal M. C. Nayak G. Panda G. V. Suryanarayana D. P. Das 《Journal of polymer science. Part A, Polymer chemistry》1982,20(1):53-62
Vinyl polymerization of acrylonitrile initiated by the Ce(IV)/thioacetamide redox system has been investigated in aqueous sulfuric acid in the temperature range of 10–20°C. The rate of polymerization (Rp) and the rate of Ce(IV) disappearance (?RCe) were measured. The effect of certain water-soluble organic solvents, added electrolytes, and aromatic and heterocyclic organic nitrogen compounds on the rate of polymerization has been investigated. Depending on the experimental results, we have suggested a suitable reaction scheme for the system which involves the production of initiating radicals from the oxidation of thioacetamide (TAm) by ceric ion and the termination of the polymer chain by metal ions. 相似文献
7.
Padma L. Nayak Rajani K. Samal Mohan C. Nayak 《Journal of polymer science. Part A, Polymer chemistry》1979,17(1):1-7
The kinetics of thermal polymerization of methyl methacrylate initiated by the redox system Mn(III)–glycerol was studied in aqueous sulfuric acid in the temperature range of 30–40°C, and the rates of polymerization, Rp, and Mn3+ disappearance, etc., were measured. The effect of certain water-miscible organic solvents and certain cationic and anionic surfactants on the rates of polymerization has been investigated. A mechanism involving the formation of a complex between Mn3+ and glycerol whose decomposition yields the initiating free radical with the polymerization being terminated by the metal ion has been suggested. 相似文献
8.
JPC – Journal of Planar Chromatography – Modern TLC - A sensitive high-performance thin-layer chromatographic (HPTLC) method has been developed for estimation of amentoflavone, an... 相似文献
9.
10.
Kinetics of polymerization of methyl methacrylate initiated by Mn3+/1,2-propanedlol has been investigated in aqueous sulfuric acid at the temperature range of 25–35°C. The rate of polymerization (Rp) and the rate of manganic ion disappearance (-RMn) have been computed. The effects of organic solvents, certain cationic and anionic detergents, added electrolytes on the initial rate of polymerization, and maximum conversion have been examined. Depending on the kinetic results, a reaction scheme has been suggested involving the formation of a complex between Mn3+ and the alcohol, which subsequently decomposed in an unimolecular step to generate the initiating free-radical which initiates polymerization and termination of the growing polymer chain by metal ion. 相似文献