Iodometric Method Research Articles

A convenient reduction method for the detection of low concentration free available chlorine——utilizing sodium sulfite as a quencher

Chlorine, serving as the mainstream disinfectant, can react with dissolved organic matter (DOM) to form undeserved disinfection by-products (DBPs). Free available chlorine (FAC) concentration is crucial to ensure effective disinfection while minimizing the formation of toxic DBPs. In this study, we propose a convenient method using sodium sulfite (Na2SO3) to reduce oxidized chlorine in FAC. The molar concentration of reduced chloride ion (Cl−) was quantified directly by ion chromatography to reflect FAC concentration. Compared with common FAC detection techniques including DPD colorimetry, iodometry, and UV methods, this novel reduction method exhibits a lower detection limit and is more resistant to interference. Common water matrices, such as DOM and anions did not affect the method accuracy (< 3.6%). Furthermore, carbonaceous DBPs (C-DBPs) like regulated trihalomethanes and halogenacetic acids, unregulated aromatic chlorophenols, did not interfere with the determination of FAC by using this reduction method. This lack of interference can be attributed to the low redox potential of Na2SO3, which does not readily react with these C-DBPs. However, nitrogenated DBPs (N-DBPs) like dichloroacetonitrile displayed slight interference (the effect of common dichloroacetonitrile concentration in water on FAC was less than 0.0007 μM). This suggests that this method is well-suited for determining FAC in chlorination processes where the C-DBPs predominated. Overall, the reduction method enables precise determination of FAC and proves valuable in assessing residual chlorine levels in both laboratory and real disinfected water samples dominated by C-DBPs.

Analytical optical methods for measuring organic peroxides and hydroperoxides: An evaluation

Hydrogen peroxide, organic peroxides and hydroperoxides exhibit high reactivity and play a pivotal role in atmospheric chemistry. These compounds are formed during the oxidation of volatile organic compounds in both gaseous and aqueous phases, particularly under low NOx conditions. Their significant contribution to the mass of secondary organic aerosols (SOA) is well-documented, and they are believed to have significant health implications. Several spectrophotometric methods have been employed to measure SOA-bound peroxides in laboratory samples, but systematic comparisons are lacking. In this study, we have assessed the advantages and limitations of these methods, including the traditional and microwave-assisted iodometric methods, the 4-nitrophenyl boronic acid assay (NPBA), and the Fenton reaction-assisted ferrous-xylenol (FOX2) assay. Besides, a comprehensive evaluation of these methodologies was conducted for the first time across a substantial cohort of commercial peroxides and hydroperoxides, employing diverse solvents (namely, water, 1-propanol, acetonitrile, methanol and chloroform) to provide broader insights compared to previous work. Ultimately, the four methods were applied and compared for peroxide determination in laboratory-generated SOA resulting from gas-phase ozonolysis of α-pinene. This study opens new opportunities for future mechanistic investigation into SOA formation and reactivity.

Genetic study of Salmonella spp. Producting Betalatimase (ESBLs)

Ten isolates were collected from different clinical sources from laboratory in medicine century . These isolates were belonging to the genus Salmonella depending on morphological and biochemical tests . The antibiotic scussptibility tests against 10 antibiotics were examined , and it was found that the 60% isolates have multiple resistant to antibiotic ,(70%) of isolates were resistant to ampicillin,(50%) were resistant to augmentin ,(40%) were resistant to ceftriaxone ,(20%) were resistant to cefotaxime and (10%) were resistant to ciprofloxacin and tetracycline while all isolates showed sensitivity to piperacillin, imipenem, amikacin and erythromycin .The ability of Salmonela isolates to produce ?-lactamase enzymes were tested using iodometric method , and the results showed that all isolates produced this enzyme.The ability of these isolates to produce Extended-Spectrum ?-lactamase (ESBLs)were also determined by double disc synergy test , only five isolates produced these enzyme. Agarose gel electrophoresis showed that Salmonella isolates ?-lactamase producer have two small plasmid bands . Transformation experiments revealed that these plasmids were capable to transform E. coli MM294, an observation which indicates the ability of these plasmids to show their expression in more than one host.

Thiolated layered double hydroxide-based nanoparticles: A study on mucoadhesiveness and cytotoxicity

The aim of this study was the synthesis and characterization of thiolated Mg/Al Layered double hydroxide nanoparticles (nLDH) that can adhere to mucosal surfaces. For this purpose, initially, nLDH were synthesized and then their surface was modified with L-cysteine (Cys). Then the Cys-modified nanoparticle structure (nLDHCys) was characterized by FTIR, XRD and FE-SEM/EDS, and the amount of thiol groups was determined using the iodometric method. The cytotoxicity properties of nLDH and LDHCys were examined on cervical (HeLa), fibroblast (L929) and colon (HT29) cell lines. In addition, the adhesion of nanoparticles to mucosal surfaces has been evaluated through mucin interaction experiments and ex vivo tests on ewe vaginal tissue. The results from characterization studies prove that Cys molecule has been successfully modified on the surface of nLDH. Cytotoxicity studies demonstrated that Cys modification did not negatively affect the cell viability, and these results were extremely close to those of nLDH. Ex vivo tests on ewe vaginal tissue and mucin interaction demonstrated that nLDHCys enhanced retention on the mucosal surface. Considering their retention ability to mucosal surface and their biocompatible nature, nLDHCys is expected to play an important role as a promising option for a safe mucoadhesive nanoparticle system for biological applications in the future.

Development of a smartphone-based colorimetric detection for quantification of vitamin C in dietary supplements and skin care products

This research project presents a development of an assay tool for quantification of vitamin C in dietary supplements and skin care products. The proposed method was developed based on decolorization of acidic potassium permanganate (KMnO4) by vitamin C through a redox reaction, with subsequent colorimetric detection by using digital imaging. The imaging was carried out using smartphone camera and free-downloaded RGB color detector application. To obtain optimal conditions, influential parameters such as light source position installed inside a 19 cm × 46 cm × 10 cm lightbox, reagent concentrations, and reaction time were studied. To the best conditions, good linearity (r2 &gt; 0.99) in the range 1–70 mg vitamin C/L was obtained. Relative standard deviation was less than 3.9% indicating high precision. The proposed method was validated by quantification of vitamin C content in 15 sample solutions using the proposed method in comparison with the reference iodometric titration method. The results obtained from those two methods were not significantly different using paired t-test at confidence level of 95% (texp=0.41, tcrit=2.14). The results indicated that utilizing smartphone camera with free-downloaded color detector application is possible as an alternative analysis tool for determination of vitamin C.

Evaluation of antioxidant potential of anthocyanin-rich hydro ethanol extract of Syzygium cumini fruit pulp in various in vitro models and in food supplement enriched with omega-3 fatty acids

Omega-3 fatty acids have immense health benefits but are highly susceptible to oxidation due to high degree of unsaturation in their molecular structure. Therefore, development of omega-3 fatty acids fortified stable functional food is a challenging task. The aim of the study was to evaluate antioxidant potential of anthocyanin-rich hydro ethanol extract of Syzygium cumini fruit pulp extract in various in vitro models and in omega-3 fatty acids enriched food supplement in bulk oil and oil-in-water emulsions model systems along with chemical analysis of the fruit pulp extract and evaluation of its cytotoxic potential, if any. The in vitro antioxidant potential was evaluated by DPPH radical scavenging, ABTS°+ decolorization and Fe2+ ion chelating methods. Antioxidant activity against oxidation of omega-3 fatty acids enriched food supplement in bulk oil and oil-in-water emulsions model systems was evaluated by monitoring primary oxidation, secondary oxidation and total oxidation of the omega-3 enriched oil using AOCS guidelines and iodometric method. Chemical analysis was performed by HR-LCMS analysis technique. Cytotoxic potential was evaluated by Allium cepa test. The test extract exhibited varying degrees of antioxidant activity in various in vitro models as well as against oxidation of omega-3 fatty acids enriched food supplement both in bulk oil and oil-in-water emulsions model systems. Chemical analysis revealed the presence of three major tentatively identified compounds malvidin-3,5-diglucoside, delphinidin-3,5-diglucoside and peonidin-3,5-diglucoside as major components of the extract. Test extract did not show any cytotoxic potential at recommended dosage level with LC50&gt; 1000 µg/ml. The results provide evidence that anthocyanin-rich hydro ethanol extract of Syzygium cumini fruit pulp may serve as a potential source of safe and effective, novel natural antioxidant for retarding oxidation of omega-3 fatty acids enriched food supplement which subsequently may help to develop omega-3 fortified stable functional foods in food industry.

КОМБИНИРОВАННЫЕ ТВОРОЖНО-ОВОЩНЫЕ ЗАПЕКАНКИ ИЗ МЕСТНОГО СЫРЬЯ ДЛЯ РАЦИОНАЛЬНОГО ПИТАНИЯ

The aim of the study is to develop a recipe for combined curd-vegetable casseroles from local raw materials with improved organoleptic and physicochemical properties. A comprehensive study was conducted that allowed theoretically and experimentally substantiating the feasibility of using turnips as a functional ingredient in the preparation of curd-vegetable casserole. The following quality indicators were studied in the experimental samples of culinary products: mass fraction of fat, protein, total sugars, ascorbic acid content; sanitary and microbiological indicators: the number of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM), the number of yeast and mold fungi, and coliform bacteria (BGCP). The applied research methods are the mass fraction of fats according to GOST 31902-2012, the mass fraction of protein by the Kjeldahl method according to GOST 10846-91, the mass fraction of ascorbic acid was determined by titration with a solution of sodium 2,6-dichlorophenolindophenolate according to GOST 24556-89, the mass fraction of sugars – by the iodometric method, by diluting the sanitary and microbiolo¬gical indicators of QMAFAnM according to GOST 10444.15-94, counting the colonies of mold fungi and yeast according to GOST 10444.12-2013 and coliform bacteria according to GOST 31747-2012. The study was carried out at the Department of Public Catering Technology and Processing of Plant Raw Materials of the Federal State Budgetary Educational Institution of Higher Education "BashSAU", Republic of Bashkortostan. In the recipe for making cottage cheese and vegetable casserole, carrots were replaced with turnips in a ratio of 25 to 100 %. It was found that 100 % replacement of carrots with turnips in a culinary product improves organoleptic properties (taste, color) and physicochemical indicators (increase in vitamin C by 5.5 times). Sanitary and microbiological indicators (QMAFAnM, coliform bacteria, yeast and mold) corresponded to the required SanPiN 2.3.2.1078-01 standards.

Oxygen Measurement in Cuprate Superconductors Using the Dissolved Oxygen/Chlorine Method

We have developed a dissolved oxygen (DO) method with differential equation (DE) correction. We measured the oxygen content in La-based and Y-based superconductors, and succeeded in measuring the oxygen content simply in one-third of the time required by the iodometric titration method. However, there was a problem with Bi-based superconductors where the measured oxygen content was smaller compared to the iodometric titration method. We hypothesized that not only O2 but also Cl2 gas is generated when dissolving Bi-based superconductors and developed a dissolved oxygen/chlorine (DO/Cl) method with DE correction. This method uses only a dissolved oxygen sensor and a dissolved chlorine sensor to measure the dissolved oxygen and dissolved chlorine content in Bi2Sr2−xLaxCuOy, allowing for the calculation of copper valence and oxygen content. The results from the DO/Cl method with DE correction show that the measured copper valence and oxygen content differ very little from those obtained using the iodometric titration method, with discrepancies within 0.016 and 0.008, respectively. Additionally, this method reduces the measurement time by one-third compared to the iodometric titration method. The results demonstrate that the DO/Cl method with DE correction can effectively measure the copper valence and oxygen content in cuprate superconductors, and using hydrochloric acid as the experimental solution is superior to sulfuric acid and nitric acid.

Estimation of the of Beta-Lactamase Production in Staphylococcus aureus Isolates from Blepharitis Patients

In this study, 90 eyelid swabs were obtained from patients with blepharitis of both sexes and various age groups who were admitted to various hospitals, and other primary healthcare centers between September 2023 and February 2024, in Babylon governorate. It was found that blepharitis occurs in all age groups and affects both sexes without any differences between them, but it is clear that blepharitis is more prevalent in the age range of (20 to 49) years old. It was discovered that out of the 90 samples, 75 (83.3%) had positive bacterial cultures, and 15 (16.7%) had no growth at all. Also, Staphylococcus aureus was the most common bacteria 39 (52%), followed by Haemophilus influenzae 17 (22.7%), Streptococcus pneumoniae 10 (13.3%), Klebsiella pneumoniae 7 (9.3%), and only 2 isolates of Streptococcus pyogenes (2.7%). The rapid iodometric method has been employed to investigate the production of beta-lactamase enzyme by the common bacteria Staphylococcus aureus, which was isolated from the eyelid's margin of patients with blepharitis. It was found that 36 (92.3%) of the 39 Staphylococcus aureus isolates had the ability to produce β-lactamase. A number of common beta-lactam antibiotics, such as penicillin, amoxicillin, ampiclox cephalexin, and cefazolin have also been used to investigate the ability of Staphylococcus aureus to produce the β-lactamase enzyme. The results showed that all isolates of Staphylococcus aureus were 100% resistant to penicillin, cephalexin and cefazolin. whereas some isolates 30 isolates were resistant to ampiclox (77%), and only 23 isolates were resistant to amoxicillin (59%).

The rheological characteristics of the dough for semi-finished biscuits with the addition of crickets flour

The article proposes to study the influence of new protein-containing raw materials, namely cricket flour (CF) Acheta domesticus on the quality of whipped flour semi-finished product (WFP) research methods. The study used generally accepted methods for determining the rheological properties of the dough: the dependence of viscosity on shear stress, temperature, and rate of deformation of the dough, as well as the elasticity of finished products and physicochemical properties of the finished semi-finished product. The mass fraction of moisture was determined by drying to constant weight. The mass fraction of ash not dissolved in 10% hydrochloric acid in absolute dry matter was determined using the dry method in a muffle furnace. The mass fraction of protein was determined by the Kjeldahl method. Alkalinity was determined by the titrometric method. The mass fraction of total sugar was determined by the iodometric method. During the manufacture of WFP, cricket flour was added to 5.0-15.0%. The results of rheological parameters showed that adding CF to the dough in an amount of 15.0% significantly affected the viscosity and plasticity of the dough, which led to a decrease in volume and porosity in the finished semi-finished product. According to physicochemical parameters, it was found that with increased BC concentration, the mass fraction of protein increases (from 4.4% in conventional WFP to 62.06% with the addition of CF in the amount of 10.0%). At the same time, the mass fraction of total sugar decreases. The mass fraction of moisture in the finished semi-finished product also changes. The resiliency and elasticity of the finished products were determined by the laboratory method using the "Labor" penetrometer. According to the results of studies of resiliency and elasticity of the finished product, it was determined that the semi-finished product with the addition of 15.0% cricket flour had the lowest indicators compared to the products with the addition of 5.0% and 10.0% cricket.

Enhancing instrumental sustainability: a spectrophotometric approach for quantifying iodate in nutritionally significant salts through the adaptation of the classical iodometry method

With the primary objective of transitioning from the classical iodometric method to an instrumental approach, preserving precision in the analytical process, this study presents the development of a spectrophotometric method for quantifying iodate (iodine equivalent) in nutritionally significant salts. Therefore, the wavelengths of maximum absorption of the I3- (350.8 nm) and I3-starch (574.1 nm) complexes were determined. The complexes demonstrated stability, as indicated by the respective molar extinction coefficient values (ε) obtained over the course of the reaction time (measured up to 1h, at 5-minute intervals, and at 28°C), for concentrations ranging from 7.81×10-6 to 1.25×10-4 mols/L of KIO3. A linear correlation between concentration and absorbance was established within the specified concentration range, with detection and quantification limits defined as 0.09 and 0.29 mg/L (350.8 nm) and 0.13 and 0.39 mg/L (574.1 nm), respectively, and calculated recovery of 102.9%. The reproducibility of the method was assessed by varying the analyst, the equipment, and the analysis day. Using the developed method, it became feasible to quantify the elemental iodine equivalent in three commercially available salts commonly employed for food purposes. When compared to the classical/traditional iodometric method, the spectrophotometric method for quantifying iodate in salts showcases sustainability with minimized solvent and reagent usage, reduced waste generation, shorter analysis time, and lower sample requirements, aligning with environmentally conscious analytical practices.

Oxidation Study and Mechanism Analysis of Desulfurization Ash in Dense-Phase Tower

Dense-phase-tower desulfurization technology is an emerging semi-dry flue-gas desulfurization ash process, i.e., the flue gas is allowed to enter the desulfurization tower from the bottom up and, at the same time, is sprayed with a desulfurizing agent that undergoes an acid–base reaction with the flue gas in the ascent process. The calcium sulfite and calcium sulfate produced by the reaction and the part of the desulfurization agent that is not involved in the reaction will enter the subsequent dust removal system, and what is retained is the by-product desulfurization ash. This desulfurization ash contains a large amount of calcium sulfite, which leads to its unstable nature; it is easily oxidized and expands in volume, and, if used in the field of building materials, it will lead to cracking and other problems, so it is difficult to effectively use it. In order to solve this problem, XRF, XRD, and iodometric and other analytical methods were used to determine the specific composition of desulfurization ash, and the muffle furnace and vertical tube furnace were used to study the thermal oxidative modification of calcium sulfite in desulfurization ash, to investigate the effects of the oxygen content, reaction temperature, medium flow rate, and chloride content on the oxidation of calcium sulfite, and to analyze the thermodynamics in the high-temperature oxidation reaction. The results showed that the oxidation rate of calcium sulfite increased with higher reaction temperatures. Increased oxygen content promoted the oxidation rate, particularly at low oxygen levels. The oxidation rate of calcium sulfite correlated positively with the medium flow rate until a rate of 75 mL·min− was reached. At a reaction temperature of 420 °C and a gas flow rate of 85 mL·min−1, the oxidation conversion efficiency exceeded 89%. Chloride content significantly reduced the oxidation rate of calcium sulfite, although this inhibition weakened at temperatures above 500 °C. Kinetic analysis suggested that the oxidation reaction of calcium sulfite predominantly occurred below 500 °C. These findings have both theoretical and practical implications for the thermal oxidation treatment and disposal of desulfurization ash.

Study on removal of NO from flue gas by ferrous cysteine solution and analysis of reaction process

Wet denitrification technology has been extensively researched for its benefits in synergistically treating pollutants. As a representative complexing agent, ferrous cysteine (Fe2+(CyS)2) solution in the complex absorption method has attracted the attention of researchers. In this study, the influence of c(Fe2+):c(CySH) ratio, complexation time, initial pH value, and temperature on the NO removal efficiency and reaction process of Fe2+(CyS)2 in a bubbling reactor were investigated. The results highlighted the significance of the initial pH of the Fe2+(CyS)2 solution in denitrification efficiency, with higher pH leading to improved NO removal. The denitrification efficiency showed a volcano-like variation with increasing temperature and was not much affected by NO inlet concentration and Fe2+(CyS)2 solution complexation time. Under optimal conditions, the denitrification efficiency remained above 80 % for 3 h of continuous reaction, peaking at 98.4 %. Calculations of NO absorption capacity indicated the regeneration of Fe2+(CyS)2 solutions. Testing with iodometric and bromine-ferrous titration methods revealed that the reaction product of cysteine is cystine, maintaining material balance before and after the reaction. Experimental results validate Fe2+(CyS)2 as an effective and stable denitrification method, laying the foundation for potential industrial application.

Determination of ascorbic acid levels in oranges under different storage conditions using Redox Iodometric method

Ascorbic acid is one of the most important vitamins to the human body due to its potentially protective role as an antioxidant. Oranges by far the most important citrus species are an excellent source of ascorbic acid. The ascorbic acid in three varieties of Ghanaian local oranges was estimated after storage under four different storage conditions. The storage conditions were deep freezing, dark cupboard, open shelf and in the sun. The redox titrimetric method using potassium iodide as the titrant and starch as an indicator was employed to evaluate the ascorbic acid levels in the orange samples after two, four and six days. The result shows a decrease in the ascorbic acid content of oranges over the storage periods. The decrease was expressed as a percentage loss of ascorbic acid originally in oranges. Less ascorbic acid was lost with the refrigerated orange samples compared to the other storage conditions. A huge loss of ascorbic acid was however lost with the samples that were exposed to the sun.

Conditions of formation of Vikhoreva river and Ust-Vikhorevsky bay hydrochemical regime (Ust-Ilimsk reservoir)

Relevance. The necessity to control the hydrochemical regime of water bodies significantly affected by anthropogenic impacts. Aim. To study the spatial distribution of major ions and trace element concentrations and identify natural and anthropogenic formation factors of the hydrochemical composition of the Vikhoreva river and Ust-Vikhorevsky bay of the Ust-Ilimsk reservoir. Objects. Waters of the Vikhoreva river before and after inflow of wastewater from the Bratsk industrial zone, waters of the Ust-Vikhorevsky bay (Vikhorevskaya and Burdoyskaya parts) of the Ust-Ilimsk reservoir. Methods. Determination of micronutrients concentrations in water was performed by inductive coupled plasma mass spectrometry, mercury – by atomic absorption method. Cations and anions were determined using standard methods accepted in hydrochemical studies, Sorg – by titrimetric method, oxygen – by iodometric method. Results. In the Vihoreva river water after wastewater inflow from the Bratsk industrial zone, significant transformations of its hydrochemical composition were detected. Along the water area of river decrease of O2 concentrations (up to 0.3 mg O2/l) and increase of Сorg (up to 131 mg/l), SO42– (up to 262 mg/l), K+ (up to 10.6 mg/l), Cl– (up to 220 mg/l), Na+ (up to 240 mg/l), Mn (up to 248.5 mg/l), Cr (up to 7.4 mg/l), to a lesser extent Al (up to 224.1 mg/l), Co (up to 0.26 mg/l), Cu (up to 5.4 mg/l), Zn (up to 43.2 mg/l), Cd (up to 0.126 mg/l), Pb (up to 0.40 mg/l), Hg (up to 0.0032 mg/l) are observed. In surface waters of the Ust-Vikhorevsky bay concentrations of most components of the main ionic composition and trace elements decrease, as compared to the Vikhoreva river water. Maximum concentrations of Mn (511.5 mg/l), Fe (1567.2 mg/l), Co (0.80 mg/l), Pb (0.77 mg/l) were detected in bottom waters. The main ionic composition and trace element concentrations in the Vihoreva river water are determined primarily by anthropogenic factor. At the same time, the hydrochemical regime of the river is effected by natural factors. Inflow of both waters of the highly polluted and forming waters of the channel part of the Ust-Ilimsk reservoir impacts the hydrochemistry of the Ust-Vikhorevsky bay.

Adsorption and visible light driven photocatalytic degradation of Malachite Green and Methylene Blue dye in wastewater using magnetized copper metal organic framework

Abstract The rising concern about the environmental pollution, particularly due to the setup of more industrial sectors has grabbed the attention of scientists and researchers. Many textile businesses emit Malachite Green and Methylene Blue (MG and MB) into the atmosphere, posing serious health risks. In this study, a copper metal-organic framework doped with iron nanoparticles (Cu-MOF@Fe3O4) was synthesized utilizing the slow evaporation approach, commencing with cuprous chloride and 2-mercaptobenzimidazole in a 1:2 ratio. Cu-MOF@Fe3O4 was characterized using a variety of techniques, including FTIR, SEM, and DRS analysis. The SEM analysis showed a rough and uneven morphology for the Cu-based MOFs. The XRD analysis confirmed the crystallinity of the products. The average crystallite size for Cu-MOF, Fe3O4 nanoparticles and Cu-MOF@Fe3O4 were found to be 0.22, 1.00, and 1.00 nm. While the surface area of Cu-MOF was found to be 213.192 m2g−1 while in Cu-MOF@Fe3O4 it shows an increase, i.e., 218.268 m2g−1 as calculated through the iodometric method. A series of experiments were conducted to assess the surface area, chemical oxygen demand (COD), limit of detection (LOD) (0.065559, 0.0136), limit of quantification (LOQ) (0.198662, 0.041312), point of zero charge (PZC) (5.2), pH levels (6, 7), contact times (10, 25 min), photocatalyst dosages (0.3, 0.05 g), dye concentrations (2, 10 µg/mL), and temperature effects (50°, 90°) on the adsorption and photocatalytic degradation of MG and MB, respectively. Photodegradation of both dyes followed pseudo-second order kinetics with R 2 values of 0.9833 (MG) and 0.8875 (MB). The adsorption isotherms (Freundlich and Langmuir) for MG and MB dye were analyzed and the experimental data holds a good correlation with Freundlich isotherm. The sample application of Cu-MOF@Fe3O4 as a photocatalyst, has high efficiency, % photocatalysis (96.9 % MG, 99.4 % MB) with reusability (95–100 %) upto 10 cycles to photodegrade MG and MB dye in wastewater. To the best of our knowledge, this is the first report on the deployment of copper-based MOFs-doped with magnetite for the photocatalytic degradation of MG and MB dyes.

Biochemical analyses in the ICARDA collection of unique dried materials of lentils

Background: Among conventional grains, lentils stand out as a rich source of nutrients, boasting high levels of protein and low levels of carbohydrates. They serve as an excellent meat alternative and are abundant in macronutrients, micronutrients, and bioactive phytochemicals. The red lentil seed coat surpasses other legumes in phenol content, showcasing remarkable antioxidant activity. Recognized as a high-level functional crop, lentils demonstrate efficacy in mitigating various health issues, including hypertension, cardiovascular disease, diabetes, and cancer. Objective: This study aims to analyze the biochemical and bioactive components, such as proteins and monosaccharides, in selected lentil varieties that thrive in the conditions of the Ararat Valley and hold economic value. The objective is to evaluate their potential as functional foods. Methods: This study was conducted at the Scientific Centre of Vegetables and Industrial Crops in Darakert, Armenia, from 2021 to 2022, and used a block-randomized design with 4 replications. Lentil seeds were planted in mid-May, with proper care and optimal spacing. Harvested in mid-July, lentil fruits underwent biochemical analysis in the laboratory. Investigated lentil varieties included those from ICARDA collection and locally bred ones. Total protein, protein nitrogen, and carbohydrate content were determined using Kjeldahl’s, Bernstein’s, and Ofner's iodometric methods, respectively. Results: The investigation into the biochemical properties of the selected lentil varieties revealed protein levels ranging from 20.5% to 23.9%, non-protein content between 1.2% and 1.6%, and monosaccharides ranging from 6.2% to 6.7%. Conclusions: Economically valuable lentil varieties, both sourced from the ICARDA collection (Flip 2007-12L, Flip 2007-3L, Flip 2007-30L, EP-54, Sell from1767L) and locally bred varieties that are registered in the State Register of Breeding achievements of Armenia (Talini-6, Haykakan88), exhibit high concentrations of key biochemical properties such as proteins, non-proteins, and monosaccharides. When considering their potential as functional foods with various health benefits, these varieties align well with contemporary nutritional trends emphasizing the inclusion of health-promoting ingredients in diets. Further research and development in this area hold the promise of not only expanding the agricultural and culinary landscape in Armenia but also contributing to the broader conversation around nutrition and functional foods around the world. Keywords: lentils, biochemical properties, protein, non-protein, monosaccharides

Гуанідінійвмісний олігомер як інгібітор мікробної корозії металу

Guanidinium-containing oligomers, a poorly studied class of organic compounds, have attracted attention due to their bactericidal properties. A guanidinium-containing oligomer based on an aliphatic oligoepoxide is a newly synthesized substance with bactericidal activity, which gives it the prospects for use as a microbial corrosion inhibitor. Aim. The goal of the study was to synthesize oligomeric alkyl substituted guanidinium bromide and study of its anticorrosive properties in the presence of steel under the influence of corrosive active sulfate-reducing bacteria. Methods. The guanidine-containing alkyl substituted oligomer was obtained by the reaction of the aliphatic oligoepoxide DEG-1 with guanidine, followed by interaction with alkyl bromide. The anticorrosive properties of the guanidine-containing oligomer were studied using collection strains of sulfate-reducing bacteria: UCM B-11503 Desulfovibrio sp.10, UCM B-11501 Desulfovibrio desulfuricans DSM642, and UCM B-11502 Desulfovibrio vulgaris DSM644. The sulfate-reducing bacteria were grown on Postgate В medium for 14 days at a temperature of 28 ± 2 °C. The number of bacteria was determined by the method of tenfold dilution. The corrosion rate was determined by the gravimetric method. The physicochemical parameters of pH and redox potential of the bacterial culture liquid were studied by the potentiometric method. The accumulation of hydrogen sulfide in the culture liquid was determined by the iodometric method. Lipolytic activity was studied spectrophotometrically using a KFK-3 device by reaction with p-nitrophenyl palmitate, catalase activity — using 0.03% hydrogen peroxide, which formed a stable colored complex with a 4% molybdenum diphosphate solution. The specific activity of the studied enzymes was expressed as unit ∙ mg-1 protein. Protein was determined in the supernatant by the conventional Lowry method. Results. It was shown that the oligomer based on aliphatic oligoepoxide has biocidal properties. A significant inhibition of the development of sulfate-reducing bacteria (SRB) was observed after the oligomer was added; only dozens of bacterial cells were detected in the medium after the exposure period. The corrosion rate of steel in the presence of SBR without addition of inhibitors was 0.15 — 0.35 mg/cm2∙h. The addition of DPC (a quaternary ammonium compound based on N-decylpyridinium chloride) (Kyiv Polytechnic Institute (KPI), Ukraine) to the culture medium led to a decrease in the steel corrosion rate to 0.032 — 0.047 mg ∙ cm-2 h-1 (by 6.5—10.6 times). In the presence of Armohib CI-28 inhibitor (based on Diamine Ethoxylate) (Akzonobel, Holland), the corrosion rate was reduced to 0.02—0.039 mg ∙ cm-2 h-1 (by 4.2 — 12.7 times). The addition of guanidinium-containing oligomer to the medium with bacteria reduced the corrosion rate to 0.075—0.079 mg/cm2 ∙ h (by 2.5—2.7 times). According to the mass loss of steel samples, the degree of metal protection against microbial corrosion in the presence of guanidinium-containing oligomer was 60.15—63.17%. Conclusions. The obtained data indicate that the guanidinium-containing oligomer based on aliphatic oligoepoxy has biocidal and anticorrosive properties and is promising for use as a means of combating microbially induced corrosion.

Introducing gradient Er ions and oxygen defects into SrCoO3 for regulating structural, electrical and magnetic transport properties.

The SrCoO3-δ system has broad application potential due to its diverse crystal structures, oxidation stoichiometric ratio, and significant electrical and magnetic properties. However, it faces the challenges of a complex crystal structure and oxygen defect control in this material system. Herein, we introduce oxygen defects into SrCoO3-δvia Er doping to regulate the structural, electrical and magnetic transport properties. Sr1-xErxCoO3-δ (x = 0-0.25) undergoes an evolution of structure and oxygen content (measured using the iodometric method) from hexagonal SrCoO2.626 (H + Co3O4) to cubic perovskite Sr0.9Er0.1CoO2.689 (CP) and finally to ordered tetragonal Sr0.8Er0.2CoO2.635 (OT). Among the three phases, Sr0.9Er0.1CoO2.689 (CP) exhibits the lowest resistivity, only 4.06 mΩ cm at room temperature, which is attributed to its high three-dimensional symmetry, overlap of O 2p and Co 3d orbitals at high oxygen ion concentration. Further introduction of Er ions and oxygen defects promotes the transformation from low spin Co4+ (LS, t52ge0g, S = 1/2) to high spin Co3+ (HS, t42ge2g, S = 2), and from the CoO6 octahedron (low magnetic moment transformation) to the CoO4.25 tetrahedron (high magnetic moment). The oxygen-deficient CoO4.25 layer appears, which can enhance the ordering of A sites and oxygen vacancies, and the CP phase transforms into room-temperature ferromagnetic Sr0.8Er0.2CoO2.635 (OT, TC∼330 K). Er ions provide unpaired electrons in the 2f orbital, which results in a strong magnetization of Sr0.8Er0.2CoO2.635 (OT, 4.66 μB/Co) at low temperatures.

Electrochemical Removal of Dissolved Oxygen for the on-Site Sensing of Free Sulfites in Wines

Sulfites are a commonly used anti-oxydants, food preservatives and anti-browning agents in the food industry (dried fruits and vegetables, pickles and beverages). Sulfites play also an important role in the preservation of wines as they are used at various stages of the winemaking process to protect the wine from oxidation and help the preservation of its flavors, aromas, and color. Sulfites are present in wines as ‘free’ or they can be bound to carbohydrates, lipids, or proteins. Only the free form is active in the wine protection. Winemakers must check, the ‘free’ and total sulfite content of their wine to make sure that the concentration of sulfite is sufficiently high to protect the wine and that the total sulfite concentration is not above the maximum authorized concentration. Samples are thus sent regularly to specialized laboratories for analysis. We report here the development of an electrochemical sensor for the on-site detection of free sulfites in wine.The electrochemical determination of free sulfite can be achieved by either oxidation or reduction. The presence of many interferents (ascorbates, polyphenols) complexifies the determination based on its oxidation, while determination by reduction is simpler as dissolved oxygen is the sole interferent. However, the electrochemical signal of sulfite reduction may be hidden by the reduction of dissolved oxygen. In laboratory conditions, the interference of dissolved oxygen is usually eliminated by displacement through the bubbling of an inert gas (e.g. Ar or N2). However, as sulfite is a gas under acidic conditions, nitrogen bubbling may also remove it from the samples. We report here the principle of the electrochemical removal of dissolved oxygen in the vicinity of a sensing electrode, making on-site detection possible [1]. The local elimination of dissolved oxygen was achieved at a platinum mesh electrode distant from the sensing electrode by 250 µm. The reduction potential was carefully optimized to allow the diffusion of sulfite through the mesh and its detection at the sensor electrode. With such an experimental set-up, the amperometric response for free sulfite in wines was linear in the 7.5 – 200 mg L-1 concentration range and with a limit of detection of 7.5 mg L-1. The samples were analyzed in less than 5 minutes without the need for solution purging with an inert gas, confirming the advantage of local elimination of dissolved oxygen for on-site analysis. A series of 27 wines (14 reds and 13 whites) from various regions of France was analyzed and the results were validated by conventional iodometric titration. Our amperometric sensor demonstrated that there were no interferences other than the one from dissolved oxygen, which is removed. Even ascorbic acid, which is a major interferent for the iodometric method, did not alter the amperometric response [2].The electrochemical system was tested in an independent winery (Dahlenheim, France) to confirm the ability to perform on-site analysis in a representative working environment. The on-site results were validated by both amperometric and iodometric analysis in the lab. The ease of use and versatility of the sensor open possibilities to use this method for the detection of other food additives (e.g. nitrite), which determination is hindered by the presence of dissolved oxygen, in other types of foodstuff.[1] M. Etienne, T.X.H. Le, T. Nasir, G. Herzog, Electrochemical Filter To Remove Oxygen Interference Locally, Rapidly, and Temporarily for Sensing Applications, Anal. Chem. 92 (2020) 7425–7429. https://doi.org/10.1021/acs.analchem.0c00395.[2] J. Gajdár, G. Herzog, M. Etienne, Amperometric Sensor for Selective On-Site Analysis of Free Sulfite in Wines, ACS Sensors. 7 (2022) 2209–2217. https://doi.org/10.1021/acssensors.2c00611.