METHOD OF QUANTITATIVE DETERMINATION OF THE SUM OF TANNINS IN EUTERPE OLERACEA FRUITS

Fruits of Euterpe oleracea are widely used in foreign medical practice as an antioxidant. The fruits of Euterpe contain tannins. The most common method of quantitative determination of tannins is spectrophotometry. The purpose of this work is to determine the content of the sum of tannins in the fruits of Euterpe by spectrophotometry Quantitative determination of the amount of tannins in the fruits of Euterpe by direct spectrophotometry was carried out. To confirm the presence of tannins in the fruits of Euterpe, qualitative reactions were used (1% solution of iron-ammonium alum, 1% solution of vanillin in concentrated hydrochloric acid). The presence of tannins was confirmed by direct spectrophotometry in extracts from euterpe fruits, the analytical maxima of the studied compounds were determined at about 282±2 nm, which corresponds to the maximum absorption of catechin. The optimal conditions for the extraction of tannins from the raw materials of this plant (extractant – ethyl alcohol 40%; the ratio of "raw material – extractant" – 1 : 100; extraction time – 60 minutes; the degree of grinding of raw materials – 1.0 mm) are justified. It was determined that the average error in determining the content of tannins in the fruits of euterpe with a confidence probability of 95% is ±1.59%. It was revealed that the content of tannins in the fruits of euterpe is 8.90%.

Crystallized Ammonium Alum and Recovery of Ammonium Alum: Urea DES from Cellulose/DES Solution

Recycling and/or recovery of solvent are of important aim in the area of environment or cost. Deep eutectic solvents (DES’s) have been widely employed in different research or industrial area. Ammonium alum: urea DES has been researched for possible applications therefore; recovery of this DES is attempted in this paper. Ammonium alum: urea DES was separated to its constituents by crystallization of ammonium alum from a solution containing cellulose. Urea was obtained by evaporation. The crystallization occurs by adding water which breaks the hydrogen bonding of DES. Water was added in a 1.25:1 volume ratio and the resulting crystals and solid materials were examined with ATR-IR and X-Ray Diffraction.

Дослідження хемосорбційних властивостей волокнистих сорбентів для очищення стічних вод від іонів Fe3+

Create new eco-friendly composite fibrous materials with sorption properties in relation to heavy metal ions in wastewater of industrial enterprises. To study the sorption capacity of synthetic fibers with respect to iron compounds. By the analytical methods determined the content of Fe3+ in model solutions of ferric ammonium alum before and after treatment, calculated the degree of exhaustion solution, %; by means of IR-spectroscopy, synthetic fibers were investigated before and after treatment with vegetable polyphenols of Tara, Quebracho and Fe3+ compounds to determine the mechanism of interaction. The proposed method of modification of fibrous materials have based on the treatment of material with tannins solutions with different nature vegetable polyphenols. It was determined that the sorption capacity of the fiber sorbent in relation to Fe3+ after treatment with of Tara tannins at a temperature of 40oC is higher than after treatment with Quebracho tannins under similar conditions. Processing during the first four hours is most effective. In this case, the degree of exhaustion solution of ferric ammonium alum reaches 90 %. The obtained sorbent has such advantages as high sorption activity and the ability to further modify, the methods of production are quite simple and cheap, and the possibility of producing sorbent from secondary raw materials allows to solve the problem of waste disposal.

Ammonium alum in alum-treated wooden artefacts: discovery, origins and consequences

Alum-treatment was extensively applied to archaeological wood from the Oseberg collection in the early 1900s, and was a common conservation method at the time involving impregnating objects with hot concentrated solutions of potassium alum (KAl(SO4)2⋅12H2O). This now obsolete consolidation method has led to dramatic long-term consequences, heavily affecting the state of preservation of the historical wooden artefacts, and dedicated chemical characterisation campaigns have been undertaken to better understand the degradation processes and aid development of re-treatment strategies. Analyses with Fourier transform infrared spectroscopy (FTIR), elemental microanalysis, and ion chromatography (IC) was performed, suggesting the presence of ammonium alum (NH4Al(SO4)2·12H2O) in many alum-treated wood samples, though no record exists of use of ammonium compounds during treatment of the artefacts. C/N rations of 1.70–68.8 in wood samples, and ammonium alum contents between 8 and 84% of the alum component and 23–168 mmol/100 g of total sample suggested that objects were actually treated with various mixes of potassium and ammonium alum. The two alums have similar properties, and in model studies of their behaviour under the conditions of alum-treatment appeared to form similarly acidic solutions, thus the different alum mixtures probably did not significantly influence object treatment. Nor have we observed other indications of unusual degradation pathways related specifically to the presence of ammonium alum. Nonetheless, investigations into potential re-treatment of the archaeological objects must be adjusted accordingly.

Synthesis of nano-alumina powder via recrystallization of ammonium alum

In the present study, a recrystallization method was implemented to recover alumina powder from ammonium alum crystal. The ammonium alum was completely dissolved in water and treated by ultra-sonication to prevent the agglomeration of the alum crystal. The white precipitate was dried at 150 °C for 6 h, and calcinations at different temperatures were performed for 2 h. The XRD results indicated the crystalline structure of alumina with two main phases: γ-Al2O3 and α-Al2O3 at 800 and 1200 °C, respectively. The N2 adsorption/desorption isotherm results indicated that the surface area for the powder in the γ phase, which can be applied in catalysts, was 142.5 m2/g, while, in the α-phase, it was 15.3 m2/g. The morphologies elucidated that the powder particles were widely distributed in the range of ≤160 nm at different calcination temperatures and this may be attributed to increments in the particle agglomeration as the calcination temperature increased.