Application of a nickel hexacyanoferrate(II) composite ion exchanger to fast separation of Ra from Fr and Ba from Cs

Sorption studies of Ra, Ba, Fr and Cs on nickel hexacyanoferrate(II) composite ion exchanger from hydrochloric acid and EDTA solutions are presented.     

Extraction of actinium with di (2-ethylhexyl) phosphoric acid from hydrochloric and nitric acid solutions

The extraction of actinium with HDEHP from Cl^– and NO ₃ ^– systems has been investigated. It was found that extraction of actinium from HCl solutions is much better than from HNO₃ solutions. Stability constants of the actinium complexes Ac(X^–)²⁺, X^–=Cl^– or NO ₃ ^– , were determined. Our results show that actinium formed less stable complexes with Cl^– than with NO ₃ ^– ligands.     

On line ion exchange separation of short-lived Zr, Hf, Mo, Ta and W isotopes as homologs of transactinide elements

The short-lived isotopes of W and their descendants have been separated from nuclear reaction products arising in the bombardment of samarium target with²⁴Mg ions at the U-400 cyclotron of JINR-Dubna. Chemical separations were performed using previously elaborated fast and continuous ion exchange. In similar way products of²³⁵U fission, obtained at the microtron MT-25 during irradiation of²³⁵U target with photoneutrons were separated.     

Induction of the Prenylated Stilbenoids Arachidin-1 and Arachidin-3 and Their Semi-Preparative Separation and Purification from Hairy Root Cultures of Peanut (Arachis hypogaea L.)

Prenylated stilbenoids such as arachidin-1 and arachidin-3 are stilbene derivatives that exhibit multiple pharmacological activities. We report an elicitation strategy using different combinations of cyclodextrin, hydrogen peroxide, methyl jasmonate and magnesium chloride to increase arachidin-1 and arachidin-3 production in peanut hairy root cultures. The treatment of hairy root cultures with cyclodextrin with hydrogen peroxide selectively enhanced arachidin-1 yield (132.6 ± 20.4 mg/L), which was 1.8-fold higher than arachidin-3. Similarly, cyclodextrin combined with methyl jasmonate selectively enhanced arachidin-3 yield (178.2 ± 6.8 mg/L), which was 5.5-fold higher than arachidin-1. Re-elicitation of the hairy root cultures further increased the levels of arachidin-1 and arachidin-3 by 24% and 42%, respectively. The ethyl acetate extract of the culture medium was consecutively fractionated by normal- and reversed-phase column chromatography, followed by semi-preparative HPLC purification on a C18 column to yield arachidin-1 with a recovery rate of 32% and arachidin-3 with a recovery rate of 39%, both at higher than 95% purity. This study provided a sustainable strategy to produce high-purity arachidin-1 and arachidin-3 using hairy root cultures of peanuts combined with column chromatography and semi-preparative HPLC.     

Hypsizygus marmoreus as a Source of Indole Compounds and Other Bioactive Substances with Health-Promoting Activities

Hypsizygus marmoreus is an edible medicinal mushroom species with a high dietary value. In this study, the fruiting bodies of commercial and self-cultivated crops and mycelium from in vitro H. marmoreus cultures (both white and brown varieties) were evaluated. This study aimed to analyze the presence of indole compounds and other biologically active substances and determine the effect that the addition of zinc and magnesium ions to the culture medium has on the content of the tested compounds in mycelial cultures. The content of indole compounds and other organic compounds was determined using high-performance liquid chromatography, the content of bioelements was determined using flame atomic absorption spectrometry, the glucan content was determined spectrophotometrically, and the antioxidant activity of extracts was estimated using DPPH, FRAP, and ABTS methods. The results showed that H. marmoreus mycelium from in vitro cultures is a good source of indole compounds, bioelements, glucans, and lovastatin. Mycelia from in vitro cultures showed the most diverse composition of indole compounds (L-tryptophan, 5-hydroxy-L-tryptophan, tryptamine, 5-methyltryptamine, and melatonin). Additionally, in vitro cultures of H. marmoreus enriched with Zn and Mg salts increased the contents of Na, Ca, Zn, 5-methyltryptamine, melatonin, protocatechuic acid, sterols, and total glucans. Only in the case of the white variety of mycelial enriched cultures, ergothioneine and Mg levels also increased. To summarize, the content of the active compounds differed depending on the H. marmoreus variety and the tested material.     

Voltammetric characteristics and determination of clothianidin using a bismuth bulk annular band electrode regenerated in situ

Ionics - A new DP AdSV method was developed for the determination of the pesticide clothianidin (Clo) based on its nitro group reduction at the in situ renovated bismuth bulk annular band working...     

Novel Method for HPLC Analysis of Triterpenic Acids Using 9-Anthryldiazomethane Derivatization and Fluorescence Detection

Triterpenic acids are a group of secondary plant metabolites which are part of the cuticular waxes covering fruits, leaves, and flowers. To date, quantitative analysis of these compounds has often been conducted using high-performance liquid chromatography coupled with spectrophotometric detection or mass spectrometry; however, these methods have some major drawbacks. This paper reports a new method of analysis implementing derivatization with 9-anthryldiazomethane and fluorescence detection. The method consists of the extraction of analytes from a matrix, purification with anion exchanging SPE columns, and an optional step of the alkaline hydrolysis of triterpenic acid esters. The paper also describes a fast and easy method for the synthesis of the derivatization agent. The detection limits of the method presented are approximately 100-fold lower than in a similar method using ultraviolet spectrophotometry as the mode of detection. The recovery and repeatability of the method are at satisfactory levels.     

Bis(2-Chlorosulfonylphenyl) Diselenide—the Substrate for Organoselenium Sulfonamides

Abstract: Synthesis of bis(2-chlorosulfonylphenyl) diselenide (11) from 2-amino-benzenesulfonic acid was elaborated. It was shown that (11) is a good starting material for synthesis of the organoselenium sulfonamides, such as bis(2-sulfamoylphenyl) diselenides (3) and benz-2,3-azaselenathiophene 1,1-dioxides (4), being potential immunostimulants and oxidation catalysts.     

Radionuclides and heavy metal concentrations as complementary tools for studying the impact of industrialization on the environment

The aim of the study was to determine whether using chemical and radiochemical analysis of lake sediments can highlight changes in the climate. Also it was studied whether human impact on the environment can be observed and to what extent such changes are in agreement with historical data. Samples of 16 cm thick sediment cores from the Smreczynski Staw Lake were collected and divided into 1 cm thick sub-samples. The samples were air dried and homogenized. The quantitative analysis of Fe, Mn, Zn, Cr, Cu, Ni, Cd, and Pb in the digested sediment samples was made by using atomic absorption spectrometry. Simultaneously, the radioactivity of ¹³⁷Cs using gamma spectrometry and ²¹⁰Pb_uns using alpha spectrometry, were measured for sediment layer dating. Results showed that iron concentration was in the range 0.3–over 1 % (w/w), and zinc 0.01–0.05 % (w/w). Lesser concentrations were found for copper 18.37–43.6 ppm, manganese 37.5–50.7 ppm, lead 146.1–432 ppm, chromium 12.3–37.4 ppm, nickel 3.1–10.8 ppm and cadmium 0.9–34.6 ppm. Changes in ¹³⁷Cs radioactivity was in the range of 89 ± 11 to 865 ± 62 (Bq kg^?1). Sediments composition can accurately reflect (in terms of time and to what extent) air pollution and natural geo-chemical processes in the environment. However, the choice of the analysed object is crucial in this respect. The Smreczynski Staw Lake, due to its location in the mountains and hydrological situation, proved to be very useful for providing undisturbed analytical samples.     

Fine singularity analysis of solutions to the Laplace equation

We present here a fine singularity analysis of solutions to the Laplace equation in special polygonal domains in the plane. We assume piecewise constant Neumann data on one component of the boundary. Our motivation is to study the so‐called Berg effect, which is explained in the introduction. Copyright © 2014 John Wiley & Sons, Ltd.