Wyniki wyszukiwania - BazTech

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Zastosowanie spektrometrii oscylacyjnej w analizie fitozwiązków i substancji odżywczych w produktach naturalnych i spożywczych

Mazurek Sylwester, Szostak Roman

Wiadomości Chemiczne

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2023

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[Z] 77, 7-8

745--774

EN

The prevalence of lifestyle diseases and trends related to healthy eating contribute to the constant search for chemical compounds with specific biological activity. Studies are conducted on plants and substances of natural origin that have been used in medicine for millennia. Techniques of vibrational spectroscopy are an underrated group of methods enabling direct analysis of plant raw material and food in their native forms. The presented examples of Arabidopsis tissues, various species and hybrids of poplar and Cistus herb classification, as well as quantitative analyses of active compounds in plant material and pharmaceutical products and determination of physicochemical parameters of common food (i.e. milk, yoghurts, pasta and flour), demonstrate the possibility of using vibrational spectroscopy for comprehensive analysis of samples of natural origin. Typical measurement techniques and chemometric methods are briefly described in this paper. The scheme of quantitative analysis based on vibrational spectra is shown and the impact of selected experimental parameters on the accuracy of the obtained results is discussed. The imaging techniques used to analyse the changes in plant tissue structures caused by genetic mutations were also presented.

2

Dwuwymiarowa analiza korelacyjna

Czarnecki Mirosław Antoni

Wiadomości Chemiczne

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2023

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[Z] 77, 7-8

775--800

EN

This review provides fundamental information on theoretical and practical aspects of two-dimensional correlation spectroscopy (2DCOS). At first, is shown a brief development of this method since its introduction by Isao Noda in 1986. In the next part is explained the general idea of 2DCOS, and details of determination of the synchronous and asynchronous spectra from the experimental data. Next section includes comprehensive description of the properties and the rules for interpretation of the 2D correlation spectra. The most common problems with interpretation of 2DCOS spectra, and the ways of improving results of correlation analysis by a proper data pre-treatment are widely discussed. In addition, some of the most important modifications of this method like moving-window analysis and PCMW2D are described. Finally, the usefulness of the power spectra is presented. It has been shown that 2D correlation analysis is a versatile and powerful tool for data analysis and provides information not readily accessible from the original data set.

3

Zastosowanie spektroskopii FT-NIR do ilościowego oznaczania wolnych kwasów tłuszczowych w oleju słonecznikowym

Semeniuk I., Krzysiak-Warzała B., Koreń-Szwarc B., Grzywocz A.

Przemysł Chemiczny

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2016

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T. 95, nr 11

2359--2362

PL

Do oznaczania zawartości wolnych kwasów tłuszczowych w próbkach oleju słonecznikowego wykorzystano technikę FT-NIR (spektroskopia bliskiej podczerwieni z transformacją Fouriera). W otrzymanych widmach FT-NIR określono pasma charakterystyczne dla wolnych kwasów tłuszczowych. Wykorzystując modelowe próbki oleju słonecznikowego o zadanych zawartościach kwasu oleinowego, sporządzono krzywe kalibracyjne. Dokładność metody zweryfikowano, stosując potencjometrię jako referencyjną metodę analityczną.

EN

Sunflowerseed oil samples with varying content of oleic acid (0–90%) were analyzed by Fourier transformation near IR spectroscopy to det. free fatty acid content. Results of the anal. agreed with those obtained by a ref. method (potentiometry).

4

Hydratacja protonu w roztworze wodnym

Śmiechowski M., Stangret J.

Wiadomości Chemiczne

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2007

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[Z] 61, 1-2

99-116

EN

The phenomena behind proton hydration in aqueous solution are still far from being fully understood and have attracted scientific attention for many decades now. This article reviews the current state of studies of this seemingly simple system, focusing particularly on the most popular techniques applied: computational chemistry, vibrational spectroscopy and diffraction methods. The picture of proton transfer via the Grotthuss mechanism, has lately been critically examined basing on up-to-date experimental and computational data, but it is still found relevant in biological systems, e.g. in proton-transferring proteins. The lengthy and heated debate on the identity of hydrated proton in an aqueous solution has focused for many years on two isomeric structures, the so-called "Eigen cation" and "Zundel cation". The findings of the last decade have proved that these two forms coexist in a dynamic equilibrium, and that the answer to this problem may as well be in the middle. The most recent reports from the last few years are reviewed here in considerable detail.

5

Spectroscopic analysis of the sediments from the treatment of chromic wastes using ashes from the fluidised bed combustion of coal

Kulczycki A., Kowalski Z., Wzorek Z., Kozak A.

Polish Journal of Chemical Technology

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2004

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Vol. 6, nr 1

27-30

EN

The paper presents a spectroscopic analysis of the precipitate from the treatment of chromic wastes using ashes from the fluidised bed combustion of coal. A complete identification of the phase components of precipitate, originated from the Cr(III) waste neutralisation carried out by the infrared and Raman spectroscopy was performed. Based on a similar analysis of pure ash, the assignment of bands of these spectra was performed. A preliminary discussion of results was made from the point of view of nature of Cr(III) binding in ash.

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Zastosowanie metody FT-NIR w przemyśle farmaceutycznym

Leszczyński W., Marek D.

LAB Laboratoria, Aparatura, Badania

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2000

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R. 5, nr 2

22-26

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Nowoczesna analiza QA/QC przy wykorzystaniu spektroskopii FT NIR. Cz. 1: FT NIR - gdzie i dlaczego?

Leszczyński W., Marek D.

LAB Laboratoria, Aparatura, Badania

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2000

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R. 5, nr 1

9-10