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Comparative studies on some analytical methods

Thermal decomposition of powder milk

Journal of Thermal Analysis and Calorimetry
Authors: R. Macêdo, O. de Moura, A. de Souza, and A. Macêdo

Abstract  

This work present comparative results on powder milk storage quality, obtained from analytical methods. Protein content was determined conventional (Kjeldahl) and colorimetric with biuret reagent at 540 nm and integral quality by thermogravimetric and biological methods. A method was developed for the protein separation of powder milk. Powder milk was submitted to degradation processes at 45, 60 and 80°C for 20 days. The results indicated that protein content values were inconsistent if determinations by Kjeldahl and colorimetric methods and biological tests were compared. There is evidence of thermal decomposition of powder milk as detected by biological and thermogravimetric methods.

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1762 1769 Panasiuk, R., Amarowicz, R., Kostyra, H. & Sijtsma, L. (1998): Determination of α-amino nitrogen in pea protein hydrolysates: a comparison of three analytical methods

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Acta Alimentaria
Authors: Zs. Bodor, Cs. Benedek, T. Kaszab, J.-L. Zinia Zaukuu, I. Kertész, and Z. Kovacs

References A nklam , E. ( 1998 ): A review of the analytical methods to determine the geographical and botanical origin of honey . Food Chem. , 63 , 549

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Abstract  

The applicability of two nuclear analytical methods for the determination of hepatacaine hydrochloride in solution was studied, i. e. radionuclide X-ray fluorescence analysis and radiometric titrations based on precipitate formations. Methods used were evaluated on the basis of obtained sensitivity values.

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Abstract  

A novel analytical method, the substoichiometric isotope dilution mass spectrometry (SIDMS) has been proposed. This method consists of the substoichiometric separation of the element in question and the subsequent intensity measurement of a stable isotope of the element with a mass spectrometer. In SIDMS, the correction of the mass discrimination of isotope measurement is not necessary and the use of expensive enriched stable isotopes may be avoided. The validity and the usefulness of SIDMS are demonstrated by the substoichiometric extraction of iron(III) with 4-isopropyltropolone and 3,5-dichlorophenol following microwave-induced plasma mass spectrometry.

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Numerical-analytical methods based on variation approach to the tasks of mechanics of deformable solid, liquid, gas, hydro- and thermodynamics, multilinked contact and on analytical decisions of loosely-coupled tasks are presented in this paper. The suggested numerical-analytical method allows investigating on high technological level the high-strength joints with guaranteed interference (pressed, hydropressed, thermal, multilayered, autofrettaged, multi-contact (polyjoints)) at various stages of life cycle, except for recycling. Method allow: to determine mode of deformation, joint loading capacity in view of technology factor influence; to calculate parameters of technological processes with the diverse contact effects proceeding in joints, assembled by various methods.

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Abstract  

In the present work a study was made for determining colour intensities using as luminous non-monochromatic source the Cherenkov emission produced in the walls of a glass capillary which acts as luminous source itself inside of a coloured solution to be evaluated. The reproducibility of this method has been compared with the spectrophotometric assay; the relative errors of both analytical methods have been calculated for different concentrations of congo red solution in the range of minimal error, according to Ringbom's criterion. The sensitivity of this analytical method has been studied for the two β-emitters employed:90Sr/90Y and204Tl.

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Abstract  

An overview of the nuclear analytical methods oppurtunities at the University of Illinois at Urbana-Champaign is given. Undergraduate and graduate level teaching and research are highlighted. The TRIGA reactor and neutron activation analysis facilities are described in the context of this role within an inter-disciplinary environment.

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A szerzők 55 éves, dyspepsiás panaszokkal jelentkező nőbeteg esete kapcsán ismertetnek egy új gázanalitikai módszert. A tünetekben domináltak az epigastrialis teltségérzéssel, puffadással járó panaszok. Vizsgálataik eredményei alapján arra a következtetésre jutottak, hogy a vékonybél proximalis területében keletkező fokozott gázképződés következtében duodenogastricus reflux révén a gáz a gyomor felé ürül. Tömlőbe felfogott eructált gáz analitikai vizsgálatával detektálták a kiböfögött gáz magas CO2-tartalmát. A módszer új és alkalmas az eructált gáz összetételének diagnosztikai célzatú elemzésére, és további lehetőséget ad a dyspepsiás típusú betegek klinikai vizsgálatához.Orv. Hetil., 2011, 152, 443–446.

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Abstract  

A 35 MeV linear electron accelerator is used to investigate how far photon activation analysis can be used within the broad spectrum of analytical methods applied in BAM. The irradiation facilities are described. Examples are given for the application of PAA in the analysis of oxygen in metals and compared with conventional heat extraction and other nuclear analytical methods. It is further shown that PAA is a very useful tool for the analysis of traces of noble metals in Cu compared with other methods. Finally the possibilities of PAA in the field of multielement analysis are demonstrated taking ancient roman potsherds and bronze as examples. The results are compared with those of XRF and AAS. It is concluded that PAA is a valuable tool in the analysis of light elements with at least partly unique possibilities, that it can serve as an independent method for the certification of Reference Materials in many cases and that PAA can be very useful applied for multielement analysis.

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