Method for the quantitative determination of lycorine in the leaves ofUngernia severtsowii

Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, FAX (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 571–572, July–August, 1994.     

Simultaneous determination of galanthamine and lycorine in Lycoris radiata by a capillary electrophoresis with an electrochemiluminescence method

A novel capillary electrophoresis with electrochemiluminescence determination method was developed for the determination of two alkaloids based on the electrochemiluminescence signal enhancement effect of the tertiary amine group on tris(2,2′‐bipyridyl)ruthenium(II). A linear relationship between the electrochemiluminescence peak area and concentrations of galanthamine and lycorine in the range of 0.07 ～ 17 μg/mL and 0.07 ～ 18 μg/mL was obtained and the detection limit was 0.008 and 0.002 μg/mL, respectively. The method is selective, simple, and convenient. It had been successfully applied to the analysis of galanthamine and lycorine in Lycoris radiata samples purchased from a local market.     

Quantitative determination of cineol

Summary 1. A method for the quantitative determination of cineol in the raw material and in eucalyptus preparations by IR spectroscopy has been developed.2. The method possesses high accuracy and is reliable and specific.Pyatigorsk Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 15–17, January–February, 1975.     

Quantitative determination of melanin

Summary The resistance of melanin to acid attack is used in a new gravimetric procedure for the determination of melanin in animal tissues. Lipids are removed by solvent extraction after acid hydrolysis of the samples.

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Zusammenfassung Eine neue gravimetrische Methode zur Bestimmung von Melanin in tierischen Geweben wurde entwickelt, die auf dessen Widerstandsfähigkeit in saurem Milieu beruht. Die vorgeschlagene Methode ist einfach; ihre Resultate werden in absoluten Werten ohne Kalibrierung gewonnen. Sie läßt sich für verschiedene Pigmentgewebe anwenden. Das beschriebene Verfahren scheint vorteilhafter als visuelle Schätzungsmethoden und solche Verfahren zu sein, die eine Melaninauflösung vorsehen. Die Melaninkonzentration in einigen Pigmentgeweben wurde angegeben.

     

Quantitative determination of hydroxylamine

This paper is a survey of 66 studies from the literature and presents a review of the quantitative methods most widely used for the determination of hydroxylamine and its salts. Volumetric, electrochemical and spectrophotometric methods are discussed, compared and evaluated.     

Quantitative determination of fluorine in toothpastes

The quantitative CE analysis of fluorine and monofluorophosphate in toothpastes is described. Separation is performed using a Waters CIA-Pak chemistry kit with Waters Electro Osmotic Flow Modifiers on a CE instrument from Spectra Physics (Spectra-phoresis 500) at elevated temperatures up to 40 °C and at a low temperature of 10 °C. The quantitative results and the simplicity are compared for the CE method, the existing standard GC procedure described in the Official Journal of the European Communities, and the procedure employing a fluoride-ion-specific electrode.     

Quantitative HPTLC determination of selenium

The present determination of selenium in biological matrices by HPTLC with in situ fluorimetric detection is an accurate alternative method, comparable to other established methods such as photometry, polarography, neutron activation, or X-ray fluorescence analysis, gas chromatography, and atomic absorption spectrometry. The excellent sensitivity of this procedure is proved by the detection limit of 250 fg of selenium per spot (using purified 2,3,1-naphthoselenodiazole). The oxidation of organic matrices, applying a novel digestion procedure, may be carried out with little instrumental expenditure. Sample preparation steps, such as the oxidation of selenium to Se (VI) and subsequent reduction to Se (IV) do not lead to significant random or systematic errors, nor does the digestion step, if an optimized procedure is used. A recovery rate of 103% and nearly parallel calibration curves for digested selenocysteine standards compared with spiked human serum samples demonstrate the accurate quantitative preparation of a biological matrix. Any interfering metal ions can be masked by addition of chelate-forming reagents.     

Quantitative determination of organic peroxides

A method has been developed for the analysis of several important dialkyl peroxides. It involves the use of high-performance liquid chromatography (HPLC) in reversed-phase mode, with a mixture of methanol and water as the mobile phase. The assurance and sensitivity limits for each of the peroxides are given. The proposed method is fast and simple with good precision. The relative standard deviations are in the range of 1.1–3.7% for 0.01–19.2 g of peroxide per mL.     

Quantitative determination of deoxypeganine hydrochloride

A procedure has been developed for the quantitative determination of deoxypeganine hydrochloride by nonaqueous titration without the use of mercury acetate. A chromatospectrophotometric method of determining the oxypeganine hydrochloride in technical products has been developed.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 84–86, January–February, 1985.     

Quantitative determination of raffinose in cottonseed meal

A chromatographic method is proposed for the quantitative determination of raffinose in cottonseed meal. The relative error of a single determination is ±4.0%.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 698–699, November–December, 1984.     

Quantitative determination of americium in biological materials

A simple, economic and specific radiochemical method for the determination of americium in urine and other biological materials is given. The urine sample is heated in nitric acid to break down any organic complexes of actinides. Insoluble phosphates are precipitated and changed to carbonates. The carbonate solution is passed through a diglycol succinate column and americium is eluted by hydrochloric acid. The eluate is evaporated to prepare a source for counting. The proposed procedure produces high overall yield and the sensitivity of the method is about 0.74 mBq (0.02 pCi). Determination of americium in the presence of other -emitters in urine is also given.     

Quantitative determination of raffinose in cottonseed meal

A chromatographic method is proposed for the quantitative determination of raffinose in cottonseed meal. The relative error of a single determination is ±4.0%.