The Use of Ion Exchangers of the Determination of Physical-Chemical Properties of Substances, Particularly Radiotracers, in Solution. I. Theoretical

1948 ◽  
Vol 52 (2) ◽  
pp. 340-350 ◽  
Author(s):  
Jack Schubert
Keyword(s):  
Chemical Properties ◽  
Ion Exchangers ◽  
Physical Chemical

scholarly journals Born out of Fire and Ice: Polymorph Studies of the Antiviral Famciclovir

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 129
Author(s):  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Variable Temperature ◽  
Chemical Properties ◽  
Crystal Form ◽  
X Ray Diffraction ◽  
Crystal Forms ◽  
X Ray ◽  
Physical Chemical ◽  
Diffraction Patterns ◽  
Crystalline Forms

There is much interest and focus on solid forms of famciclovir. However, in spite of the abundance of reported differences in oral bioavailability, compressibility, and other physical–chemical properties of the various crystal forms of this drug, very little precise structural analysis is available in the literature to date. The form used in the commercial formulation is the anhydrous form I. Patents and patent applications report three different anhydrous crystalline forms on the basis of unindexed powder diffraction patterns. Single-crystal and variable-temperature X-ray diffraction experiments using the commercially available anhydrous form of famciclovir were carried out and led not only to the crystal structure determination of the anhydrous form I, but also to discovery of a new crystal form of anhydrous famciclovir from powder data.

scholarly journals Technology of functional bread using sorghum flour

2020 ◽  
Vol 17 ◽  
pp. 00196
Author(s):  
Olga Temnikova ◽  
Elena Rudenko ◽  
Galina Mukovnina ◽  
Anna Ruzyanova
Keyword(s):  
Mathematical Modeling ◽  
Daily Intake ◽  
Chemical Properties ◽  
Optimal Dosage ◽  
Sorghum Flour ◽  
Physical Chemical ◽  
Functional Bread

The production of functional bread is considered in this paper. It is suggested to make bread using mix of wheat and sorghum flour. Mathematical modeling of experiment in order to calculate the optimal dosage of sorghum flour in the recipe was carried out. It was established that introduction of sorghum flour allows decreasing the amount of sugar in the recipes. The determination of physical-chemical properties of bread samples was conducted. Acidity, wet content and porosity of bread samples were determined. Obtained bread can be classified as functional because the portion of the bread contains more than 15 % of magnesium, manganese and silicon daily intake.

CAFFEINE ANALYSIS BY THIN-LAYER CHROMATOGRAPHY RELATED TO THE PHYSICAL-CHEMICAL PROPERTIES OF DIFFERENT VARIETIES OF COFFEE AND SURROGATES

2017 ◽  
Vol 31 (1) ◽  
pp. 69-73
Author(s):  
Cristina Mihali ◽  
◽  
Ionut Grad ◽  
Thomas Dippong ◽  
◽  
...  
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Chemical Properties ◽  
Chemical Characteristics ◽  
Physical Chemical ◽  
Different Types ◽  
Decaffeinated Coffee ◽  
Layer Chromatography

The aim of this study was to evaluate the physical-chemical characteristics of different types of coffee, decaffeinated and of two types of coffee substitutes based on barley and chicory. The following physical-chemical characteristics were performed: moisture, pH, content of polyphenols and qualitatively determination of caffeine, by thin-layer chromatography. The moisture of the investigated coffee and substitutes of coffee was in the range 1,5 and 3,6%. By analyzing the moisture of the coffee substitutes, we observed that coffee based on barley has the highest moisture and chicory has the lowest value. The caffeine was qualitatively determined by thin-layer chromatography. It was found that all types of the investigated samples contain caffeine excepting decaffeinated coffee. Polyphenols content of the analysed coffee samples varied in the range of 2.8-3.2 mg/g.

Harmonization of the Standardization of Reference Substances for the Analysis of Pesticide Products

1985 ◽  
Vol 68 (5) ◽  
pp. 907-910
Author(s):  
Konrad Pavel
Keyword(s):  
Reference Materials ◽  
Chemical Properties ◽  
Quality Criteria ◽  
Reference Substance ◽  
Working Standard ◽  
Food And Agriculture ◽  
Physical Chemical ◽  
Food And Agriculture Organization ◽  
Primary Reference

Abstract Quantitative analysis of pesticide products is often based on analytical procedures that require substances of precisely known purity as reference materials. In addition, samples of "pure" active ingredient (AI) are needed for registration purposes, in part for the determination of some physical-chemical properties, and also for submission to the authorities. Pure AIs from several pesticides are available commercially or from particular institutes. Some pure pesticides, especially those of newly developed products, must be provided by the manufacturer. Substances like these have a variety of names, such as pure AI, pure pesticide, reference material, pure standard, or analytical grade sample. It is suggested that internationally uniform names be given to highly purified substances and to other samples that are used as reference materials for determination and certification of purity and other quality criteria. DAPA recommends that 2 kinds of reference materials be distinguished: primary reference substance and working standard, and offers draft guidelines for standardization and draft certification forms for reference materials. Finally, it is proposed that CIPAC (Collaborative International Pesticides Analytical Council) or FAO (Food and Agriculture Organization) publish corresponding papers.

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