Selection of the Second Adsorbent for Sampling Volatile Organic Compounds in the Biomass Gasification Tar Using Solid-Phase Adsorption.

The purpose of this study is to examine the effectiveness of a solid-phase adsorption method for measuring the concentrations of tar compounds in biomass. This method involves collecting tars on a column with an amino-phase sorbent. However, because biomass tar has a high concentration of volatile organic compounds, not all of them can be collected with just one column. Therefore, the researchers decided to add a second column with a different adsorbent to improve the accuracy of the measurement. They also chose to test three different sorbents (Carbopack B, Carbotrap, and activated coconut charcoal) in order to determine which one is the most effective for determining the concentration of volatile organic compounds. The desorption efficiency from various sorbents, the adsorption efficiency of the studied compounds on each sorbent depending on the sampled gas temperature, and the maximal amounts of compounds adsorbed on activated coconut charcoal were evaluated. The best results were obtained using activated coconut charcoal. A modified sampling device consisting of 500 mg of the amino-phase adsorbent and 100 mg of activated coconut charcoal was selected as the optimal choice for collecting tar, including its volatile organic compounds, from the synthesis gas generated during biomass gasification.

Synthesis and Properties of New 3-Heterylamino-Substituted 9-Nitrobenzanthrone Derivatives.

In the present study, new fluorophores based on disubstituted benzanthrone derivatives were designed starting from 9-nitro-3-bromobenzanthrone with nucleophilic substitution of the bromine atom with some secondary cyclic amines. It has been found that this reaction is positively affected by the presence of a nitro group in comparison with 3-bromobenzanthrone. The new compounds exhibit intense absorption and pronounced luminescent properties in various organic solvents. In this regard, their photophysical properties were evaluated with an experimental study of the solvatochromic behavior of the obtained compounds in various solvents. It has recently been found that the addition of an electron-withdrawing nitro group to the benzanthrone core increases its first- and second-order hyperpolarizability. Such dyes can be used in the fabrication of optical limiter devices. Therefore, the developed fluorescent molecules have a potential prospect for extensive application in optoelectronics.

Heterocyclic Schiff Bases of 3-Aminobenzanthrone and Their Reduced Analogues: Synthesis, Properties and Spectroscopy.

New substituted azomethines of benzanthrone with heterocyclic substituents were synthesized by condensation reaction of 3-aminobenzo[de]anthracen-7-one with appropriate aromatic aldehydes. The resulting imines were reduced with sodium borohydride to the corresponding amines, the luminescence of which is more pronounced in comparison with the initial azomethines. The novel benzanthrone derivatives were characterized by NMR, IR, MS, UV/Vis, and fluorescence spectroscopy. The structure of three dyes was studied by the X-ray single crystal structure analysis. The solvent effect on photophysical behaviors of synthesized imines and amines was investigated. The obtained compounds absorb at 420-525 nm, have relatively large Stokes shifts (up to 150 nm in ethanol), and emit at 500-660 nm. The results testify that emission of the studied compounds is sensitive to the solvent polarity, exhibiting negative fluorosolvatochromism for the synthesized azomethines and positive fluorosolvatochromism for the obtained amines. The results obtained indicate that the synthesized compounds are promising as luminescent dyes.

A Simple and Rapid Staining Technique for Sex Determination of Trichinella Larvae Parasites by Confocal Laser Scanning Microscopy.

The roundworms of Trichinella genus are worldwide distributed and their prevalence in nature is high. Trichinella genus parasites are the causative agents of foodborne zoonosis trichinellosis. The main prevention and control of the infection are meat inspection by the magnetic stirrer method for the detection of Trichinella larvae in muscle samples. The treatment can be effective if the parasite is discovered early in the intestinal phase. Once the Trichinella larva has reached the muscle tissue, the parasite remains therein and there is no treatment for this life cycle stage. The Trichinella species is dioecious with separate male and female individuals. The developed staining technique that uses confocal laser scanning microscopy (CLSM) displays sufficient results for Trichinella larvae examination and this protocol is applicable to study the internal and external structures and for the sex determination of T. britovi and T. spiralis larvae samples. In the present study, a luminescent derivative was synthesized and used for staining of T. spiralis and T. britovi larvae samples for the examination by CLSM. Various fixatives, such as AFA, 70% ethanol, and Bouin's and Carnoy's solutions were tested for sample preparation. The synthesized luminescent compound demonstrates best visualization results for samples fixed in Bouin's fixative.

Novel dye for detection of callus embryo by confocal laser scanning fluorescence microscopy.

In the present study a new luminescent dye 3-N-(2-pyrrolidinylacetamido)benzanthrone (AZR) was synthesized. Spectroscopic measurements of the novel benzanthrone 3-aminoderivative were performed in seven organic solvents showing strong fluorescence. The capability of the prepared dye for visualization has been tested on flax, red clover and alfalfa to determinate the embryo in plant callus tissue cultures. Callus cells were stained with AZR and further analysed utilizing confocal laser scanning fluorescence microscopy. Performed experiments show high visualization effectiveness of newly synthesized fluorescent dye AZR that is efficient in fast and relatively inexpensive diagnostics of callus embryos that are problematic due to in vitro culture specificity.

Experimental and theoretical study on structure and spectroscopic properties of 2-bromo-3-N-(N',N'-dimethylformamidino) benzanthrone.

The goal of present research is a theoretical and experimental investigation of geometrical structure, electronic properties, absorption and fluorescence spectra prediction for 2-bromo-3-N-(N',N'-dimethylformamidino)benzanthrone. As a result of conformational analysis, two rotamers have been found with a rotational barrier of 5.45 kcal/mol. Absorption and fluorescence spectra maxima in the solvent (ethanol) have been calculated using the concepts of the Jablonsky diagram. The obtained values of the absorption and fluorescence maxima (437 and 679 nm, respectively) correspond to the experimental values (447 and 659 nm). The abnormally large Stokes shift is associated with the redistribution of electron density, as well as flattening of the structure of the molecule in the excited state. According to the frontal molecular orbital analysis data, the peak in the long-wave part of the absorption spectra is created by an electron transition from the highest occupied molecular orbital (HOMO) to the lowest occupied molecular orbital (LUMO) (π→π*). Substitute group does not participate in the formation of absorption and fluorescence spectra.

Novel luminescent dyes for confocal laser scanning microscopy used in Trematoda parasite diagnostics.

Benzanthrone derivates are now widely used in many industrial and scientific applications as dyes for polymers and textiles. In biochemical, biomedical and diagnostics investigations benzanthrone dyes are used as a lipophilic fluorescent probe since many benzanthrone derivates demonstrate bright fluorescence and they have ability to intercalate between membrane lipids. The aim of research presented here was to assess the luminescence ability of benzanthrone derivatives using microscopic visualization of biological objects. Accordingly, specimens of freshwater trematodes: Diplostomum spathaceum, Diplodiscus subclavatus and Prosotocus confusus, were stained by novel benzanthrone dyes using different fixatives. The samples were examined under a confocal laser scanning microscope. All of the dyes tested demonstrated good results for digestive and reproductive system visualization. Based on obtained results we conclude that benzanthrone dyes could be used for internal and external structure confocal laser scanning microscopic imaging of trematode specimens.