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151.
152.
Rao KN Gopinath R Kumar MS Suryanarayana I Prasad PS 《Chemical communications (Cambridge, England)》2001,(20):2088-2089
A titania-supported ammonium salt of 12-molybdophosphoric acid has been synthesized, and the salt-support interaction, which enhanced the reaction rate, has been correlated with the activity of the catalyst in the ammoxidation of 2-methylpyrazine. 相似文献
153.
154.
Summary A quadratic composition dependence of the electrical resistivity of amorphous transition metal alloys has been investigated
at room temperature. A very good agreement between the theoretical and the observed values has been obtained in the case of
NixZr1−x and CuxZr1−x for all compositions. The thermoelectric power was then correlated with the electrical resistivity satisfactorily for the
CuxZr1−x and NixZr1−x
To speed up publication, the authors of this paper have agreed to not receive the proofs for correction. 相似文献
155.
156.
G. Saravanan M. V. Suryanarayana M. J. Jadhav M. Ravikumar N. Someswararao P. V. R. Acharyulu 《Chromatographia》2007,66(5-6):431-434
This present work describes the development of a stability-indicating high performance liquid chromatographic method for the
quantitative determination of pemetrexed disodium. Pemetrexed disodium is an antifolate antineoplastic agent that exerts its
action by disrupting folate-dependent metabolic processes essential for cell replication. The chromatographic separation was
achieved on an ACE 3 C18 HPLC column using a mobile phase consisting of a mixture of buffer (solvent A) and organic modifier
acetonitrile (solvent B). Forced degradation studies were performed on bulk sample of pemetrexed disodium using acid (0.5 N
hydrochloric acid), base (0.5 N sodium hydroxide), oxidation (10% v/v hydrogen peroxide), heat (60 °C) and UV light (254 nm). Degradation of the drug substance was observed in base hydrolysis.
Degradation product formed under acid and base hydrolysis was found to be starting material. The stressed samples were assayed
using the developed LC method and the mass balance found was close to 99.5%, thus proving its stability-indicating power.
The developed method was validated with respect to linearity, accuracy, precision and robustness. 相似文献
157.
Chilukuri S. P. Sastry Tipirneni A. S. R. Prasad Mulukutla V. Suryanarayana 《Mikrochimica acta》1990,100(1-2):107-112
A rapid, simple, precise, accurate and highly sensitive method for the determination of some antihistaminic agents such as dimethindene maleate (DMM), embramine hydrochloride (EMH), isothipendyl hydrochloride (IPH), mebhydrolin napadisylate (MHn), methdilazine hydrochloride (MDH), promethazine hydrochloride (PMH), trimeprazine tartrate (TMT) and triprolidine hydrochloride (TPH) in bulk samples and pharmaceutical preparations is proposed. The method is based on the formation of a chloroform-soluble ion-association complex between the antihistaminic agent and Fast Green FCF at pH 5.0 with an absorption maximum at 620 nm. The composition of antihistaminic agent and Fast Green FCF in each ion-association complex is studied. The relative standard deviation of the proposed method is less than 1.3%, the percent recovery is 99.4–100.2% and the results are not significantly different from the standard methods at the 95% confidence level. 相似文献
158.
Suryanarayana MV Venkataraman S Reddy MS Reddy BP Sastry CS Krupadanam GL 《Talanta》1993,40(9):1357-1360
A liquid chromatographic method is described for the evaluation of Astemizole purity. The method is also applicable for the analysis of pharmaceutical dosage forms of Astemizole using indole as internal standard. Separation was achieved with a micro bondapak C(18) column and phosphate buffer (pH 6.0):acetonitrile (50:50 v/v) as eluent, at a flow rate of 1.5 ml/min with UV detection at 280 nm. The method is suitable for estimating the possible impurities if any present in Astemizole up to 0.05% for 1a and 0.25% for 1b. The method is simple, rapid and accurate for the analysis of Astemizole. 相似文献
159.
Summary From nitric or hydrochloric acid medium thorium is quantitatively precipitated by N-phenylanthranilic acid in the range of pH 1.5–3.4 as a light yellow compound, which can be dried to a definite composition, Th(C13H10NO2)4, at 110° C. This has been utilized for the direct gravimetric estimation of thorium and its separation from uranium(VI), cerium(III), aluminium and iron at a pH of ca. 2.0–2.5.This method is superior to most of the existing methods for the estimation of thorium since quantitative precipitation occurs at a relatively low pH and the thorium compound, which has a high molecular weight, can be weighed directly, thus making possible the determination of rather small quantities (ca. 5 mg) of thorium with fair accuracy (error less than 1%).
Zusammenfassung Thorium kann aus salpeter-oder salzsaurer Lösung im pH-Bereich 1,5–3,4 mit Hilfe von N-Phenylanthranilsäure als hellgelber Niederschlag quantitativ ausgefällt werden. Der Mederschlag kann bei 110°C zu definierter Zusammensetzung getrocknet werden [Th(C13H10NO2)4]. Diese Fällung wurde zur direkten gravimetrischen Bestimmung von Thorium und seiner Trennung von Uran(VI), Cer(III), Aluminium und Eisen bei pH 2,0–2,5 benutzt. Das Verfahren ist den meisten bekannten Methoden überlegen, das die Fällung bei relativ niedrigem pH durchgeführt und die Thoriumverbindung (die ein hohes Molekulargewicht hat) direkt gewogen werden kann. Kleine Mengen Thorium (etwa 5 mg) können mit recht guter Genauigkeit bestimmt werden (Fehler kleiner als 1%).相似文献
160.
Gravimetric determination of lead (5–100 mg) by homogeneous precipitation of lead sulphate from a solution containing lead(II), EDTA and sulphate by destructive oxidation of EDTA with hydrogen peroxide or sodium bromate is described. Aluminium(III), iron(III), zinc(II), manganese(II), copper(II), nickel(II), tin(II) and antimony(III) do not interfere in the method. The method can successfully be applied to the analysis of type metal. 相似文献