Group Of Compounds Research Articles

The unusual suspects: Screening for persistent, mobile, and toxic plastic additives in plastic leachates

Plastic additives are a diverse group of chemical compounds added to plastic products to give them their unique physical-chemical properties. Persistent, mobile, and toxic (PMT) plastic additives are a highly polar, environmentally stable sub-group of plastic additives with a variety of uses in plastic products. Due to their mobility into water, they can pose a significant long-term risk to the aquatic environment. Despite the potential threat, PMT plastic additives remain largely unregulated and under-studied. Notably, there is a need for dedicated analytical methodology and leaching studies to determine their potential emission from plastic products. Here we present an optimized leaching protocol and novel instrumental analysis method for the screening of 124 PMT plastic additives registered for use in Canada using high performance liquid chromatography with quantitative time-of-flight mass spectrometry (HPLC-QToF-MS). The analytical method covered a log Kow/Dow range between 0.21 and 6.02, which covered 72% of the PMT plastic additives used in Canada. A total of 52 PMT plastic additive suspects were leached in the optimization experiments, 44 of which were unique based on accurate mass and retention time. The conditions that resulted in the greatest numbers of PMT plastic additives leached were lake water, UV light exposure, and a timeframe of approximately 30 days. The analytical and leaching methods presented here offer new tools to study PMT plastic additives and assess their leaching in an environmentally relevant matrix, which can inform monitoring, threat assessment, and regulatory efforts moving forward.

Assessment of Antimicrobial Activity of Lycopene, Vitamin E, and Lycopene-Vitamin E Combination Against Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, and Candida albicans: An In Vitro Study.

Background Lycopene is a naturally occurring compound classified as a carotenoid, a group of pigments responsible for the vibrant colors observed in many fruits and vegetables. It is most commonly associated with red-colored fruits and vegetables, such as tomatoes, watermelon, pink grapefruit, and papaya. Vitamin E encompasses a group of chemical compounds that share a structural relationship with alpha-tocopherol and are essential for the proper functioning of the human body. It is a fat-soluble vitamin and is known for its antioxidant properties. The aim of this study is to evaluate the antimicrobial activity of lycopene extract, vitamin E extract, and their combination against oral pathogens for their potential application in the treatment of oral diseases. Materials and methods The potential antimicrobial effects of extracts derived from lycopene, vitamin E, and their combination were evaluated against oral commensals like Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, and Candida albicans. Three concentrations (25 μl, 50 μl, and 100 μl) of the extract were tested. Mueller-Hinton agar (MHA) and Rose Bengal agar (RBA) bases were utilized to determine the zone of inhibition.And the experiments were repeated in triplicate for each group. Results The identification and assessment of the antimicrobial activity of lycopene extract, vitamin E extract, and their combination revealed the greatest efficacy at the highest concentration (100 μl) against all tested microbial strains. Notably, C. albicans exhibited the highest susceptibility compared to the other strains. Vitamin E had the least antimicrobial effect and combination had the highest antimicrobial effect. Conclusion The results of our study demonstrated substantial antimicrobial activity of lycopene and vitamin E. These findings suggest that lycopene and vitamin E can be harnessed in the development of diverse drug formulations for the treatment of oral diseases.

Analisis Rendemen dan Skrining Senyawa Metabolit Sekunder Ekstrak Metanol Daun Violces (Viola odorata)

Violces (Viola odorata) is an herbal plant from the Violaceae family and is used in traditional medicine. This is believed to be due to the presence of phytochemical compounds in the Violces plant that provide the pharmacological activity. This study aims to determine the extract yield value and chemical compound groups contained in Violces leaves. The research method consists of four stages, namely extraction, evaporation, yield value calculation, and phytochemical screening. Violces leaf extract was obtained by maceration for 3 days using methanol as the solvent, then filtered and concentrated using a rotary evaporator. The concentrated extract of Violces leaves was then used to calculate the yield value and subjected to phytochemical screening for alkaloids, flavonoids, tannins, saponins, steroids and terpenoids. The method used for the identification of secondary metabolite compounds involve the use of chemical reagents, indicated by color changes, precipitate formation, foam/bubbles, and rings. The results of the study showed a methanol extract yield of Violces leaves of 26,70%. The phytochemical screening test of the methanol extract of Violces leaves revealed the presence of tannins, saponins and steroids.

A Determination of the Caffeine Content in Dietary Supplements According to Green Chemistry Principles.

Caffeine is a natural psychoactive substance that belongs to a group of chemical compounds called purine alkaloids. Caffeine is found in various plants such as coffee, tea, cocoa, guarana, and yerba mate. It is often added to dietary supplements for its ability to increase metabolism and aid in weight loss. To determine the caffeine content in dietary supplements, a novel UHPLC method was developed, compatible with the rules of green analytical chemistry. The developed method used only water and ethanol for sample preparation and chromatographic separation on a short C18 column. The obtained method confirmed that caffeine may be analyzed using only environmentally friendly solvents, ethanol, and water. The developed method is characterized by its low limit of quantitation, equal to 0.047 µg/mL, and good reproducibility (a relative standard deviation lower than 1.1%). The obtained results show that the caffeine content in tested dietary supplements is 4-35% higher than the declared amount in most cases. In comparison, the caffeine content of the drug determined using this method was performed with an accuracy of 0.4% RSD.

Ionic Liquids as Environmental Pollutants-Analysis of the Effect of Tetrabutylammonium Chloride on the Growth and Development of Wheat and Cucumber.

Ionic liquids are a huge group of chemical compounds that have found, or may, in the future, find, applications in various industries. These compounds are characterized by excellent physical, chemical, and biological properties, but a big problem is their environmental impact. One of the representatives of this group of compounds is tetrabutylammonium chloride ([TBA][Cl]). In this present study, the effects of [TBA][Cl] were evaluated on two popular plant species-a monocotyledonous plant-wheat (Triticum aestivum L.) and a dicotyledonous plant-cucumber (Cucumis sativus L.). The results showed that the compound caused a pronounced inhibition of plant growth and roots, as well as plant fresh weight yield. An increase in plant dry weight was observed at the same time. Despite the decrease in the content of photosynthetic pigments, no major changes were observed in chlorophyll fluorescence. All observed changes were strongly related to the applied concentration of the compound.

Dichrostachys cinerea (L.) Wight and Arn. (Fabaceae), a plant used in the traditional treatment of lymphatic filariasis in Côte d'Ivoire: Ethnopharmacological characteristics

Dichrostachys cinerea (L.) Wight & Arn. (Fabaceae) is a plant used in the traditional treatment of lymphatic filariasis. It was revealed following a recent ethnomedicinal survey. The present study aims to highlight the distinctive ethnopharmacological characteristics of Dichrostachys cinerea. The aim was to identify some groups of chemical compounds by thin layer chromatography, to assay some minerals and finally to characterise the specific anatomical and micrographic features of the plant. Terpenes and sterols, saponosides, flavonoids and tannins are the main phytocompounds revealed. Magnesium with 110.4 mg/100 g dry matter is the most abundant mineral. Anatomical sections revealed from the periphery to the interior of the organs, epidermis, collenchyma, cortical parenchyma, sclerenchyma, liber or phloem, the wood or xylem and the medullary parenchyma. In the plant powder, it was observed starch grains and calcium oxalate crystals. These results add to the data on Dichrostachys cinerea, a taxon much used in traditional Ivorian medicine for the treatment of lymphatic filariasis.

Ethnopharmacological Characteristics of Pycnanthus angolensis (Welw.) Warb. (Myristicaceae), a Plant Used in the Traditional Treatment of Viral and Parasitic Diseases

Background: Pycnanthus angolensis (Welw.) Warb. (Myristicaceae) is a medicinal plant used in traditional Ivorian medicine. A recent ethnobotanical survey has discovered Pycnanthus angolensis in the traditional treatment of viral and parasitic diseases.
 Aim: The present study aims to highlight the distinctive ethnopharmacological characteristics of Pycnanthus angolensis.
 Methods: The aim was to identify some groups of chemical compounds by thin layer chromatography, to assay some minerals and finally to characterise the specific anatomical and micrographic features of the plant.
 Results: Terpenes and sterols, saponosides, flavonoids and tannins are the main phytocompounds revealed. Magnesium with 621.3 mg/100 g dry matter is the most abundant mineral. Anatomical sections and plant powder revealed starch grains, calcium oxalate crystals, secretory pockets and tector hairs that are responsible for the formation of various biological substances in the plant.
 Conclusion: These results add to the data on Pycnanthus angolensis, a taxon much used in traditional Ivorian medicine for the treatment of antiparasitic and antiviral diseases.

Development and application of a novel analytical method for the determination of 8 plant sterols/stanols in 22 legumes samples

Phytosterols (PS) are a group of chemical compounds of plant origin, able to reduce blood levels of bad cholesterol and the consequent risk of atherosclerosis. In this study, an HPLC-DAD method was developed for the determination of cholesterol and 7 main PSs (β-sitosterol, campestanol, campesterol, fucosterol, sitostanol, stigmasterol, and stigmastanol) in legumes samples. The method was validated, and satisfactory results were obtained in terms of linearity (0.995 – 0.999), repeatability, LOD, and LOQ. Moreover, compared to standard extraction methods, an innovative extraction process of PS was developed through ultrasound-assisted extraction (UAE) allowing a reduction of extraction time by half while maintaining a high extraction efficiency. The developed PS extraction and analytical methods were applied for the first time to 22 types of legumes (beans, lentils, chickpeas, whole, or dehulled). 6 PS were observed in legumes with levels ranging from 86.4 mg kg−1 (roveja) to 699.9 mg kg−1 (black chickpeas). These results confirm that legumes should be included in the diet as great sources of cholesterol-lowering agents.

Detection and characterization of adulterants in baru and soursop oils

The presence of vegetable oils in the pharmaceutical and cosmetic industries boosts their production and commercialization, maximizing the economic potential, however to increase profits, vegetable oils with high added value are the target of adulteration practices. This negatively affects the quality of the product and compromises the bioactive properties of these oils. The objective of this study was to build partial least squares regression models to identify baru oil and soursop oil samples adulterated with soybean oil. For data collection the oils samples were characterized using portable near-infrared spectrometer and Fourier-transform infrared spectrometer. These techniques were chosen because both provide information about the functional groups of chemical compounds, however portable equipment, being cheaper, presents signals with lower spectral resolution. Thus, the objective of the work is also to verify if the results using both equipment are similar. The developed regression models were effective; however, the near-infrared technique presented some limitations in the identification of soursop oil. This is because for the construction of his model it was necessary to use a smaller number of variables and levels of adulteration. Nevertheless, high R² values and relatively low errors were obtained for all models, making it possible to identify the adulteration.
 
 Pratica Application: Adulteration analysis of baru and soursop oils by infrared spectroscopy and portable equipment

The Effect of Y Content on Structural and Sorption Properties of A2B7-Type Phase in the La-Y-Ni-Al-Mn System.

Metal hydrides are an interesting group of chemical compounds, able to store hydrogen in a reversible, compact and safe manner. Among them, A2B7-type intermetallic alloys based on La-Mg-Ni have attracted particular attention due to their high electrochemical hydrogen storage capacity (∼400 mAh/g) and extended cycle life. However, the presence of Mg makes their synthesis via conventional metallurgical routes challenging. Replacing Mg with Y is a viable approach. Herein, we present a systematic study for a series of compounds with a nominal composition of La2-xYxNi6.50Mn0.33Al0.17, x = 0.33, 0.67, 1.00, 1.33, 1.67, focusing on the relationship between the material structural properties and hydrogen sorption performances. The results show that while the hydrogen-induced phase amorphization occurs in the Y-poor samples (x < 1.00) already during the first hydrogen absorption, a higher Y content helps to maintain the material crystallinity during the hydrogenation cycles and increases its H-storage capacity (1.37 wt.% for x = 1.00 vs. 1.60 wt.% for x = 1.67 at 50 °C). Thermal conductivity experiments on the studied compositions indicate the importance of thermal transfer between powder individual particles and/or a measuring instrument.

Phytochemical Composition of Combretum molle (R. Br. ex G. Don.) Engl. & Diels Leaf and Stem Extracts.

The demand for medicinal plants is on a rise due to their affordability, accessibility and relatively non-toxic nature. Combretum molle (Combretaceae) is used in African traditional medicine to treat a number of diseases. This study aimed to screen the phytochemical composition of the hexane, chloroform and methanol extracts of C. molle leaves and stems using qualitative phytochemical screening. Additionally, the study aimed to identify the functional phytochemical groups, determine the elemental composition and provide a fluorescence characterization of the powdered leaves and stems by performing Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray (EDX) microanalyses and fluorescence microscopy. Phytochemical screening revealed the presence of alkaloids, flavonoids, phenolic compounds, polyphenols, terpenoids, tannins, coumarins, saponins, phytosterols, gums, mucilage, carbohydrates, amino acids and proteins within all leaf and stem extracts. Lipids and fixed oils were additionally present within the methanol extracts. FTIR demonstrated significant peaks in absorption frequency in the leaf at wavelengths of 3283.18, 2917.81, 1617.72, 1318.83, 1233.97, 1032.32 and 521.38 cm-1, and in the stem at 3318.91, 1619.25, 1317.13, 1032.68, 780.86 and 516.39 cm-1. These corresponded to the functional groups of chemical compounds including alcohols, phenols, primary amines, alkyl halides, alkanes and alkyl aryl ethers, corroborating the presence of the detected phytochemicals within the plant. EDX microanalyses showed the elemental composition of the powdered leaves (68.44% C, 26.72% O, 1.87% Ca, 0.96% Cl, 0.93% Mg, 0.71% K, 0.13% Na, 0.12 % Mn and 0.10% Rb) and stems (54.92% C, 42.86% O, 1.7% Ca, 0.43% Mg and 0.09% Mn). Fluorescence microscopy provided a characteristic evaluation of the plant in its powdered form and revealed distinct colour changes in the material when treated with various reagents and viewed under ultraviolet light. In conclusion, the phytochemical constituents of the leaves and stems of C. molle confirm the suitability of this species for use in traditional medicine. The findings from this study suggest the need to validate the use of C. molle in the development of modern medicines.

Chemical Characterization and Several Bioactivities of Cladanthus mixtus from Morocco

The purpose of this work was to investigate, for the first time to our knowledge, the chemical composition and bioactivity of methanolic extracts (roots, stems, leaves, and flowers) from Cladanthus mixtus (L.) Chevall. that grows wild in northern Morocco (the Tangier-Tetouan-Al Hoceima region). The phenolic and flavonoid contents were determined by spectrophotometer methods, and the composition of derivatized methanolic extracts from C. mixtus using N-O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) was analyzed by gas chromatography-mass spectrometry (GC-MS). The antioxidant activity was carried out by applying the 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and DPPH (2,2-diphenyl-1-picrylhydrazyl) tests. The micro-dilution technique was chosen to investigate the antimicrobial activity of methanolic extracts against two bacterial strains and three fungal species. The results showed that the values of total phenolic and flavonoid contents were found to be higher in flower extracts (30.55 ± 0.85 mg of gallic acid equivalents (GAE)/g of dried weight (DW) and 26.00 ±1.34 mg of quercetin equivalents (QE)/g DW, respectively). Other groups of chemical compounds were revealed by GC-MS, such as carbohydrates (27.25-64.87%), fatty acids (1.58-9.08%), organic acids (11.81-18.82%), and amino acids (1.26-7.10%). Root and flower methanolic extracts showed the highest antioxidant activity using ABTS (39.49 mg of Trolox equivalents (TE)/g DW) and DPPH (36.23 mg TE/g DW), respectively. A positive correlation between antioxidant activity and polyphenol and flavonoid amounts was found. Antibacterial tests showed that the best activity was presented by the leaf extract against Staphylococcus aureus (minimum inhibitory concentration (MIC) = minimum bactericidal concentration (MBC) = 20 mg/mL) and Escherichia coli (MIC of 30 mg/mL and MBC of 35 mg/mL). S. aureus was more sensitive to the extracts compared to E. coli. All extracts showed antifungal activity against Trichophyton rubrum, with the best efficacy reported by the flower and leaf extracts (MIC = 1.25 mg/mL and minimum fungicidal concentration (MFC) = 2.5 mg/mL). In general, extracts of C. mixtus appeared less effective against Candida albicans and Aspergillus fumigatus.

Urinary bio-monitoring of aromatic amine derivatives by new needle trap device packed with the multi-component adsorbent

Aromatic amines are a large group of chemical compounds that have attracted the attention of researchers due to their toxicity and carcinogenicity. This study aimed to develop an efficient method for sampling and analysis of aromatic amines (Aniline, N, N-dimethylaniline, 2-chloroaniline, and 3-chloroaniline) from the vapour phase (headspace) of urine samples. For the implementation of this plan, a needle trap device packed with the three-component adsorbent consisting of nano-Hydroxy Apatite (nHA), Zeolite (Ze), and Metal–Organic Framework (MOF) equipped with GC-FID was employed for the first phase. Examination of the prepared adsorbents was performed by FT-IR, PXRD, and FE-SEM techniques. The optimal value of considerable parameters such as time and temperature of extraction, salt content, and pH were established using the Response Surface Methodology-Central Composite Design (RMS-CCD) method. In this way, the optimal extraction of targeted analytes was accomplished in 41 min at 41 °C with NaCl content of 33.0% (w/v) and pH: 13.0, respectively. Also, the repeatability and reproducibility of the method were calculated to be in the range of 2.2–7.1% and 3.9–8.1%, respectively, which indicates the acceptable precision of the method. Also, the limit of detection (LOD) and limit of quantification (LOQ) were determined in the range of 0.3–32.0 ng.L−1 and 0.8–350.0 ng.L−1, respectively, which proves the high sensitivity of the proposed method. Furthermore, the recovery percent of the extracted analytes was concluded in the range of 97.0–99.0% after 6 and 30 days of the sampling and storage at 25 °C and 4 °C, respectively. Finally, the designed procedure was employed in the analysis of the above-mentioned aromatic amines in the real urine samples. The achieved results illustrate that the three-component absorbent system (nHA;Ze;MOF@NTD) can be introduced as an efficient, fast-response, sensitive, and versatile procedure for trace analysis of the different aromatic amine compounds in public and occupational health.

Determination of Polycyclic Aromatic Hydrocarbon Content in Garden Herbal Plants Using Liquid Chromatographic Analysis (HPLC-FL).

Polycyclic aromatic hydrocarbons (PAHs) are a group of chemical compounds generated as a result of the incomplete combustion of fossil fuels or wood. PAHs are known for their negative effect on living organisms, including teratogenic, carcinogenic and mutagenic activity. The objective of this study is to determine the contamination of three popular herbal species showing pro-health properties, i.e., lavender, parsley and mint, with polycyclic aromatic hydrocarbons, collected from three different backyard gardens in Poland. The concentration of PAHs in plant material was determined by high-performance liquid chromatography with a fluorescence detector (HPLC-FL). The concentration of eleven PAHs in plant material was determined with high-pressure liquid chromatography after extraction using the QuEChERS purification technique. Mint collected within an area of a mining and energy production complex (the city of Konin) was characterized by the highest Σ of 11 PAHs, equaled to 902.35 µg/g FW, with anthracene being the most abundant compound. However, it contained the lowest sum of PAHs, among all tested plants, with high carcinogenicity. Parsley from the city of Poznań showed the highest content of benzo[a]pyrene (BaP), showing the strongest carcinogenicity, while the highest value of BaP equivalent was calculated for mint collected in Konin. The obtained results suggest that the level and profile of plant contamination with PAHs depend on the species and the location of herb cultivation. In particular, mining and energy industry facilities are sources of PAHs, which contaminate plant material for further direct use or as bioactive herbal extracts.

The Effectiveness of Kersen Leaf Extracts (Muntingia calabura L.) on Cutting Wounds Infected with Sthapylococcus Aureus Bacteria

One of the plants that has been used by the community is cherry (Muntingia calabura L.) which is a lush plant, easy to breed, often on the side of the road, allowed to grow as a shade tree. Traditionally used to treat bleeding wounds, festering and burns, inflammation of the walls of blood vessels accompanied by blood clots in their channels. Fresh or dried cherry leaves are used as a medicine for wounds by finely grinding them and placing them on the wound. The use of cherry leaves directly in the treatment of wounds is not liked by the community, so they tried to formulate it in the form of cream preparations. Based on this, the researchers conducted a phytochemical screening and formulation of cherry leaf extract in cream preparations as well as tested its effectiveness for treating wounds. Extraction was carried out by percolation using 80% ethanol. Phytochemical screening was carried out on fresh leaves, simplicia, and ethanol extract of cherry leaves. And formulated into cream preparations with concentrations of 2.5%, 5% and 7.5%. The effectiveness for wound healing was carried out on artificial incisions on the back skin of male guinea pigs infected with Staphylococcus aureus bacteria. Measured decrease in wound diameter and observation of the width of the pus and the amount of edema. The results of the phytochemical screening test showed that there were the same groups of chemical compounds in fresh leaves, simplicia, and ethanol extract of cherry leaves, namely alkaloids, flavonoids, tannins, triterpenoids/steroids. The greater the concentration of EEDK in the cream, the faster the wound will heal. On the 16th day, 5% EEDK; 7.5%; and gentamicin provide 100% perfect wound healing. Means that the ethanol extract of cherry leaves at a concentration of 5% has a very good ability to heal incisions infected with Staphylococcs aureus.

The results of the field accounting of medicinal plants in the forest and forest-steppe zones of Central Russia

To assess the potential of the raw material base of medicinal plants and search for new plant sources of biologically active substances, it is necessary to monitor and record the biological diversity of plants, their number and abundance in natural plant communities. Plants are counted by the transect method. In the course of field research in 2022, the biodiversity, abundance, and abundance of medicinal plants in three regions of Central Russia were assessed. In the Lipetsk Region (the lower reaches of the Chichera River, the valley of the Sukhaya Lubna River), the most notable species of the Ranunculaceae families were identified: Adonis vernalis L. (spring adonis); Rosaceae: Agrimonia eupatoria L. (common agrimony); Filipendula vulgaris Moench (six-petalled meadowsweet). In the Samara region (floodplain of the Sok River) - Rosaceae: Sanguisorba officinalis L. (burnet officinalis); Filipendula vulgaris Moench; Ranunculaceae: Adonis vernalis L. In the Moscow, Ryazan region (Meshchera) species of families - Rosaceae: Potentilla argentea L. (silver cinquefoil) (Rosaceae), Fragaria vesca L. (wild strawberry), Potentilla erecta L. (upright cinquefoil), Comarum palustre L. (marsh cinquefoil); Onagraceae: Chamaenerion angustifolium (L.) Scop. (fireweed narrow-leaved); Asteraceae: Helichrysum arenarium (L.) Moench.; Caprifoliaceae: Valeriana officinalis L. (valerian officinalis); Hypericaceae: Hypericum maculatum L. (St. John’s wort); Equisetaceae: Equisetum arvense L. (horsetail); Lamiaceae: Stachys palustris L. (marsh weed); Primulaceae: Lysimachia vulgaris L. (common loosestrife). A total of 65 species of medicinal plants have been identified. Species with a noticeable abundance are characterized as a source of a certain group of chemical compounds. To assess the potential of the raw material base of medicinal plants and to search for new plant sources of biologically active substances, it is necessary to monitor and account for the biological diversity of plants, their size and abundance in natural plant communities. Accounting of plants is carried out by the transect method. In the course of field research 2022 year, the biodiversity, size and abundance of medicinal plants in three regions of Central Russia were evaluated. In the Lipetsk region (the lower reaches of the Chicher River, the valley of the Sukhaya Lubna River), the most notable species were identified - Ranunculaceae: Adonis vernalis L.; Rosaceae: Agrimonia eupatoria L.; Filipendula vulgaris Moench. In the Samara region (floodplain of the Sok river) - Rosaceae: Sanguisorba officinalis L.; Filipendula vulgaris Moench; Ranunculaceae: Adonis vernalis L. In the Moscow, Ryazan regions (Meschera) - Rosaceae: Potentilla argentea L., Fragaria vesca L., Potentilla erecta L., Comarum palustre L.; Onagraceae: Chamaenerion angustifolium (L.) Scop.; Asteraceae: Helichrysum arenarium (L.) Moench.; Caprifoliaceae: Valeriana officinalis L.; Hypericaceae: Hypericum maculatum L.; Equisetaceae: Equisetum arvense L.; Lamiaceae: Stachys palustris L.; Primulaceae: Lysimachia vulgaris L. A total of 65 species of medicinal plants have been identified. Species with a noticeable number are characterized as a source of a certain group of chemical compounds.

Application of Metal-Organic Frameworks to High-Performance Liquid Chromatography

We present a critical review of experimental studies of the efficiency of the separation of various groups of chemical compounds under the conditions of high-performance liquid chromatography using metal-organic framework polymers (metal-organic frameworks (MOFs)) or composite materials with MOFs as a stationary phase. MOFs demonstrated many advantages in high-performance liquid chromatography and a possibility of competing successfully with conventional phases, especially in the determination of low-molecular-weight compounds and optical isomers. Among the promising options for using this class of materials are the development of monolithic separation columns and hybrid adsorbents that eliminate the disadvantages of adsorbents based on pure MOFs.

ИЗУЧЕНИЕ ПАРАМЕТРОВ ОСТРОЙ ТОКСИЧНОСТИ И КУМУЛЯТИВНЫХ СВОЙСТВ ДЕЗИНФИЦИРУЮЩЕГО СРЕДСТВА «ДЕЗИНОЛ ВЕТ»

An urgent problem of veterinary science and practice is the search for new highly effective domestic disinfectants that would improve the sanitary quality of products, raw materials and feed of animal origin, as well as animal productivity and ensure the country's well-being in infectious diseases. The most promising in this regard are composite preparations containing several compatible active substances (AS) from various groups of chemical compounds. The new disinfectant «Dezinol Vet» contains glutaraldehyde, glyoxal, a mixture of QAC (alkyldimethylbenzylammonium chloride and idecyldimethylammonium chloride) as an active ingredient. When determining the acute toxicity and cumulative properties of «Dezinol Vet», it was found that at a working concentration (5.5% in water) when injected into the stomach, LD50 was more than 5000 mg/kg, which corresponds to the 4th hazard class (low-toxic compounds) according to GOST 12.1.007-76. No material cumulation of the agent was revealed, a weak functional cumulation was shown. Given that all changes have been canceled only at the level of doses and concentrations that are several times higher than recommended, it is possible to exclude the real danger of this product for animals under the conditions recommended for its use.

Brown carbon absorptivity in fresh wildfire smoke: associations with volatility and chemical compound groups

Brown carbon light absorptivity is associated with organic aerosol volatility and elemental carbon concentrations.

QUESTÕES REGULATÓRIAS SOBRE A DESINFECÇÃO DA ÁGUA E O IMPACTO DA GERAÇÃO DE DBPs NA QUALIDADE DA ÁGUA TRATADA

REGULATORY ISSUES ON WATER DISINFECTION AND THE IMPACT OF DBP GENERATION ON DRINKING WATER QUALITY. Drinking water disinfection has been viewed as one of the major advances in public health protection in history. However, while it has been very successful in assuring microbiological safety, disinfection also brought relevant concerns about chemical safety and the potential unintended health hazards associated with disinfection byproduct (DBP) exposure. DBPs represent one of the most important groups of chemical compounds to which humans are exposed through drinking water, as epidemiological studies have consistently associated long-term exposure with multiple adverse health effects. It is established that disinfection is an essential component of providing microbiologically safe drinking water and shall never be compromised. Yet, chemical safety regarding DBP exposure remains a largely uncovered and highly discussed topic. Several DBPs have been reported in the past few decades, yet research on formation, toxicity and occurrence remains scarce for most compounds. Also, for each identified DBP, many remain undiscovered. In view of an ever-growing list of DBPs and the existing gaps in available research, identifying overall driving agents of toxicity is still a major challenge for public health protection. This review attempts to provide an insight on contemporary issues regarding the overall safety of drinking water and the trade-off between microbiological and chemical risks, considering current challenges in water and sanitation access and existing regulations.