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An actual problem of medical diagnostics is that the determination of acetone concentration in air exhaled by persons. For industrial health and safety, environmental monitoring and process control Gas detection instruments are needed. Conducting polymer composites have various industrial applications. The most dangerous pollutants released each year by anthropogenic sources are benzene, toluene, nitrogen oxides, hydrogen sulfide or ammonia They have harmful effects both on human beings and animals. People may develop a headache, fatigue and even narcosis when the concentration of acetone in air is higher than 10,000 ppm. Hence, detecting and measuring acetone concentrations in the workplace or human body are necessary for our safety and health. Gas sensors play vital role in detecting, monitoring and controlling the presence of hazardous and poisonous gases in the atmosphere at very low concentrations. In the present work, a pasty solution of PVDF/ZrO2 was coated on glass plates using an Apex Spin Coating unit (SCU 2005) and the samples were tested for gas sensing. For this study, acetone, ethanol and ammonia gases were used and the electrical resistance of polymer composites over the vapours were determined using MECO 603 digital multimeter. The vapours of acetone were detected by the sensor. The sensing cycle is reversible upto to two cycles. In order to validate the selectivity of the gas sensor, polymer composite plates were exposed to ammonia and ethanol vapours which do not show any response. The PVDF / ZrO2 (PVDZr) composites were characterized by using PXRD, FTIR and SEM. The results show that the thick film of PVDZr composite can function as a very good gas sensor for acetone vapours.

In the mirabegron (MIR) synthesis, the N‐nitroso mirabegron (NNM) is obtained during synthetic process of MIR; water is being used in reaction under acidic condition. Nitrite source is from water, and secondary amine source is from MIR as it has secondary amine; NNM is generated as an impurity during the synthesis of MIR. The presence of NNM in MIR could potentially affect its effectiveness. The purpose of this study was to establish a Ultra‐performance liquid chromatography‐mass spectrometry/mass spectrometry (UPLC‐MS/MS) methodology to identify NNM in MIR samples. The method for NNM analysis was developed on Acquity HSS T3 (100*2.1) mm 1.8 μm column with gradient elution using mobile phase consisted of 0.1% formic acid in water (mobile phase A) and 0.1% formic acid in methanol (mobile phase B). Mass spectrometer with electrospray ionization operated in the MRM mode was used in the analysis of NNM (m/ z 426.20 → 170.00). The UPLC‐MS/MS methodology proposed showed a good linearity (0.02 to 0.72 ppm), good system precision (RSD = 0.57%), good method precision (RSD = 0.87%), acceptable accuracy (94.5–116.5%), low detection limit (0.006 ppm) and low quantification limit (0.02 ppm) for NNM. The UPLC‐MS/MS methodology proposed can be utilized to assess the quality of MIR sample for the presence of NNM impurity. [ABSTRACT FROM AUTHOR]

Developing affordable and high‐performance catalysts for water electrolyzers and fuel cell devices is an emerging field of research aiming for their feasible implementation and thus addressing sustainable global energy demands. Accordingly, several catalytic systems have been developed for anodic oxidation reactions and cathodic reduction reactions. Specifically, more research attention has been focused on viable catalyst synthesis processes including design, choice of precursors, reaction conditions, and regulation steps for achieving desirable properties and performances. Intriguingly, biomass has been demonstrated as a promising precursor for the potential design of different carbon‐based catalysts for electrocatalytic oxidation/reduction reactions. In this review, the recent developments in using biomass precursors to derive different nanostructures are systematically discussed. The biomass‐derived catalysts especially applied for reduction reactions (hydrogen evolution and oxygen reduction reactions) are summarized, and the impact of various catalysts' engineering routes (incorporation of metals and nonmetals into the carbon structures) on the resulting structure–performance relationship is critically discussed. Further, this review highlights the performance of various biomass‐derived catalysts toward electrocatalytic reduction reactions that unveil the catalyst's intrinsic features such as selectivity, activity, and durability. The summarized results and the critical discussion will facilitate screening of the best biomass precursor, identifying suitable regulation strategies for accomplishing desirable properties, and thus advancing the next‐generation catalysts' developments. Further, the significance, challenges, and perspectives on biomass‐derived catalysts for electrocatalysis are comprehensively discussed. [ABSTRACT FROM AUTHOR]

The drastic climate change imposing adverse environmental effects receives serious research attention for finding a suitable solution. The replacement of conventional fossil energy sources with renewable and sustainable energy sources is the potential route; and thus, manifests as a viable solution. Accordingly, the electrocatalytic carbon dioxide (CO2) reduction process coupled with the renewable energy source is an emerging strategy for adopting a sustainable approach. However, the existing challenges in designing suitable catalyst, support material, electrolyte, inadequate selectivity, and intermediate reactions of CO2 reduction demand substantial research advancement. Numerous studies reported for the CO2 reduction process highlight the importance of catalyst design and product selectivity. Importantly, the copper‐based catalysts, capable in the output of multi‐carbon products, are reported as a "star" material. This review; therefore, focuses on catalyst design strategies, unique structural/morphological features, and product selectivity of diverse copper‐based catalysts. The outstanding findings of copper‐based catalysts and the corresponding products are critically discussed with adequate figures of merits. The impact of structural/morphological features on product selectivity is discussed in detail. The future scope and author perspectives on copper‐based catalysts for the feasible electrocatalytic CO2 reduction application are summarized. [ABSTRACT FROM AUTHOR]

Fluocinolone acetonide topical is used to treat skin discomforts such as swelling, itching and redness by activating the natural substances in the skin. Several process-related impurities and degradation products are identified and reported. But hydroperoxide impurities in Fluocinolone acetonide topical solution are not reported anywhere. In this study, we identify two potential genotoxic isomeric hydroperoxide impurities in Fluocinolone acetonide topical solution by Liquid Chromatography Mass Spectrometry analysis. A possible mechanism for the formation of these two novel hydroperoxide impurities is based on the neighboring group participation effect of adjacent hydroxyl group (Internal SN2) which results in the loss of fluorine atom and formation of epoxide intermediate followed by the addition of the HOOH group. Since most of the hydroperoxide impurities are genotoxic in nature, one should eliminate these impurities from Active Pharmaceutical Ingredient (API) or protect the formulation product from these oxidative impurities. [ABSTRACT FROM AUTHOR]

A reverse phase high-performance liquid chromatography (HPLC) method has been developed for the quantification of a typical drug Dasatinib (DST) and its related impurities in pharmaceuticals. Kinetex C18 (4.6 × 150 mm, 5 μm) column was used in the chromatographic separations, using buffer (1.36 g of KH2PO4 in 1000 mL of water, pH = 7.8; adjusted with diluted KOH solution) with solvent as acetonitrile and mode of elution as the gradient. The flow rate is 0.9 mL/min, column oven temperature as 45°C and the overall gradient run time as 65 min. The developed method was found to produce symmetric and good separation between the process-related and degradation impurities. Method optimization is achieved with photodiode array at 305 nm over the concentration range of 0.5 mg/mL and degradation studies were carried out under acidic, alkaline, oxidative, photolytic and thermal conditions to demonstrate the stability indicating capability of the method. Two major impurities were found in forced degradation studies in the HPLC analysis, the unknown, acid degradants were enriched and isolated by preparative HPLC, then characterized through high-resolution mass spectrometry, nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. The unknown acid degradation impurity was showing Exact Mass of 521.11, molecular formula C22H25Cl2N7O2S and its chemical name as 2-(5-chloro-6-(4-(2-hydroxyethyl) piperazin-1-yl)-2-methylpyrimidin-4-ylamino)-N-(2-chloro-6-methylphenyl) thiazole-5-carboxamide. Another impurity (oxidative degradant) found as known DST N-oxide Impurity-L and its chemical name as 4-(6-((5-((2-chloro-6-methylphenyl) carbamoyl) thiazol-2-yl) amino)-2-methylpyrimidin-4-yl)-1-(2-hydroxyethyl) piperazine 1-oxide. The analytical HPLC method was further validated as per ICH guidelines. [ABSTRACT FROM AUTHOR]

Aims: Carvedilol phosphate (CDP) is a nonselective beta-blocker used for the treatment of heart failures and hypertension. In this work, moisture sorption–desorption characteristics and thermodynamic properties of CDP have been investigated. Materials and Methods: The isotherms were determined using dynamic vapor sorption analyzer at different humidity conditions (0%–90% relative humidity) and three pharmaceutically relevant temperatures (20°C, 30°C, and 40°C). The experimental sorption data determined were fitted to various models, namely, Brunauer–Emmett–Teller; Guggenheim-Anderson-De Boer (GAB); Peleg; and modified GAB. Isosteric heats of sorption were evaluated through the direct use of sorption isotherms by means of the Clausius-Clapeyron equation. Statistical Analysis Used: The sorption model parameters were determined from the experimental sorption data using nonlinear regression analysis, and mean relative percentage deviation (P), correlation (Correl), root mean square error, and model efficiency were considered as the criteria to select the best fit model. Results: The sorption–desorption isotherms have sigmoidal shape – confirming to Type II isotherms. Based on the statistical data analysis, modified GAB model was found to be more adequate to explain sorption characteristics of CDP. It is noted that the rate of adsorption and desorption is specific to the temperature at which it was being studied. It is observed that isosteric heat of sorption decreased with increasing equilibrium moisture content. Conclusions: The calculation of the thermodynamic properties was further used to draw an understanding of the properties of water and energy requirements associated with the sorption behavior. The sorption–desorption data and the set of equations are useful in the simulation of processing, handling, and storage of CDP and further behavior during manufacture and storage of CDP formulations.

A sensitive and robust method for determination and quantification of potential genotoxic impurities in sartans has been developed. These impurities need to be controlled at trace levels during quantification in drug substances and drug products for safe consumption. Recent regulatory requirements also suggested the need to have highly sensitive analytical method for trace level quantification of nitrosamine impurities. In this paper, we have described a simple, rapid and sensitive liquid chromatography-mass spectrometry method for six potential genotoxic nitrosamine impurities: N-Nitroso dimethyl amine (NDMA), N-Nitroso diethyl amine (NDEA), N-Nitroso Ethyl Iso propylamine (NIPEA), N-Nitroso-Nmethyl-4-aminobutyric acid (NMBA) N-Nitroso diisopropylamino (NDIPA) and N-Nitroso dibutyl amine (NDBA) in Azilsartan (AZL), Valsartan (VAL), Telmisartan (TEL), Olmesartan (OLM), Losartan (LOS) and Irbesartan (IRB) with a limit of quantification of less than 0.003 ppm. Chromatographic separation is achieved using Poroshell HPH- C18, 150 × 4.6 mm, 2.7 μm column with 0.1% formic acid in water as mobile phase A and 0.1% formic acid in methanol as mobile phase B at a flow rate of 0.5 mL/min using gradient mode of elution at a total run time of 20 min. Six nitrosamine impurities are ionized and quantified in positive mode of atmospheric pressure chemical ionization using multiple reaction monitoring. As per ICH guidelines, method validation is performed and evaluated the limit of quantification and detection and found to give good S/N ratios with good linearity range of 0.003–0.045 ppm with regression coefficient > 0.999 for all the six nitrosamine impurities. Method recoveries are also established using three-step sample preparation and are found to be satisfactory within 80–120%. The single method can be used routinely applied for the detection of nitrosamines in AZL, VAL, TEL, OLM, LOS and IRB. [ABSTRACT FROM AUTHOR]

Rhodium and its compounds have recently been reported more often than ever in the literature as hydrogen evolution reaction (HER) electrocatalysts. The recent developments in designing single-atom catalysts and catalytic materials on a sub-nanometer scale have raised a little concern about the abundance of elements in currently used catalysts. This review critically analyzes the history of Rh in HER electrocatalysis, recent progress, prospects, and unaddressed challenges. In addition, highlights on the properties that make Rh and its compounds appropriate for HER electrocatalysis and the recent trends are also detailed citing the key developments. An elaborate and opinionated outlook given at the end details the ways in which further progress with Rh and its compounds as HER electrocatalysts may occur and how it would redefine the use and scope of the same in water electrolyzers. [ABSTRACT FROM AUTHOR]