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In the era of liquid biopsy, microRNAs emerge as promising candidates for the early diagnosis and prognosis of cancer, offering valuable insights into the disease's development. Among all the existing analytical approaches, even if traditional approaches such as the nucleic acid amplification ones have the advantages to be highly sensitive, they cannot be used at the point-of-care, while sensors might be poorly sensitive despite their portability. In order to improve the analytical performance of existing electroanalytical systems, we demonstrate how a simple chromatographic paper-based disk might be useful to rationally improve the sensitivity, depending on the number of preconcentration cycles. A paper-based electrochemical platform for miRNA detection has been developed by modifying a paper-based electrode with a methylene blue (MB)-modified single-stranded sequence (ssDNA) complementary to the chosen miRNA, namely miR-224 that is associated with lung cancer. A detection limit of ca. 0.6 nM has been obtained in spiked human serum samples. To further enhance the sensitivity, an external chromatographic wax-patterned paper-based disk has been adopted to preconcentrate the sample, and this has been demonstrated both in standard and in serum solutions. For each solution, three miR-224 levels have been preconcentrated, obtaining a satisfactory lowering detection limit of ca. 50 pM using a simple and sustainable procedure. This approach opens wide possibilities in the field of analytical and bioanalytical chemistry, being useful not only for electrochemistry but also for other architectures of detection and transduction. [ABSTRACT FROM AUTHOR]

Forensic document examination has been considered one of the most important fields in the forensic science. For this, a quick, effective, and cheap techniques for evaluation of forensic evidence is highly required. This study explores the comparison of A4 document paper by chemical and physical analysis. 16 of white A4 paper from different brands were analyzed by FTIR for investigation of structural characteristics. Video Spectral Comparator 8000 has been used to compare the A4 papers under different light source. The inorganic filler composition in the paper is also explored by ICP‐OES. The calcium carbonate content in document papers play a discriminant role which found to be between 16.02 % and 35.54 %. Also, water contact angle has been utilized in order to examine the surface of paper which is generally related to the inorganic filler and other additives. The WCA results ranged between 83° and 111° that enable quick and easy way to compare A4 document papers. The experimental results have demonstrated that besides FTIR methods, other methods such as ICP‐OES for elemental composition, WCA for wetting test, VSC for visualization under different light of source could have been applied for comparison of document papers in case of criminal cases. [ABSTRACT FROM AUTHOR]

Criminal practices in which an individual becomes vulnerable and prone to sexual assault after ingesting drinks spiked with doping substances have become a social concern globally. As forensic protocols require a multi‐tiered strategy for chemical evidentiary analysis, the backlog of evidence has become a significant problem in the community. Herein, a fast, sensible, and complementary dual analytical methodology was developed using a single commercial paper substrate for surface‐enhanced Raman spectroscopy (SERS) and paper spray mass spectrometry (PS‐MS) analysis to identify psychotropic substances added to alcoholic beverages irrefutably. To study and investigate this criminal practice, pharmaceutical formulations containing distinct psychotropic substances (zolpidem, clonazepam, diazepam, and ketamine) were added to drinks typically consumed at parties and festivals (Pilsen beer, açaí Catuaba®, gin tonic, and vodka mixed with Coca‐Cola Zero®). A simple liquid–liquid extraction with a low‐temperature partitioning (LLE‐LTP) procedure was applied to the drinks and effectively minimized matrix effects. As a preliminary analysis, SERS spectra combined with Hierarchical Clustering Analysis (HCA) provided sufficient information to investigate the samples further. The presence of the protonated species for the psychotropic substances in the spiked drinks was readily verified in the mass spectra and confirmed by tandem mass spectrometry. Finally, the results demonstrate the potential of this methodology to be easily implemented into the routine of forensic laboratories and to be further employed at harm reduction tends at parties and festivals to detect contaminated beverages promptly and irrefutably as an efficient tool to prevent such crimes. [ABSTRACT FROM AUTHOR]

• An innovative disposable in-tip cellulose paper (DICP) device has been developed. • Pristine Cellulose Paper was used as bio-based sorbent for adsorption of pesticides. • Simple design, no need for energy-consuming equipment, portable, time-efficient, and compliant with White and Green Analytical Chemistry principles. • Optimized parameters ensured robust performance, impressive detection limits, and high accuracy. • Applicability was demonstrated through successful analysis of real postmortem blood samples. Accurately identifying and quantifying toxicants is crucial for medico-legal investigations in forensic toxicology; however, low analyte concentrations and the complex samples matrix make this work difficult. Therefore, a simplified sample preparation procedure is crucial to streamline the analysis to minimize sample handling errors, reduce cost and improve the overall efficiency of analysis of toxicants. To address these challenges, an innovative disposable in-tip cellulose paper (DICP) device has been developed for the extraction of three pesticides viz. Chlorpyrifos, Quinalphos and Carbofuran from postmortem blood samples. The DICP device leverages cellulose paper strips housed within a pipette tip to streamline the extraction process, significantly reducing solvent usage, time, and labor while maintaining high analytical accuracy. The extraction of pesticides from postmortem blood using the DICP device involves a streamlined process characterized by adsorption and desorption. The diluted blood samples were processed through the DICP device via repeated aspirating and dispensing calyces to adsorb the pesticides onto the cellulose paper. The adsorbed pesticides are then eluted using acetone, which is collected for GC–MS analysis. The method was meticulously optimized, achieving a limit of quantification in the range of 0.009–0.01 µg mL−1. The intra-day and inter-day precisions were consistently less than 5 % and 10 %, respectively, with accuracy ranging from 94–106 %. Relative recoveries for the analytes were observed to be between 60 % and 93.3 %, and matrix effects were determined to be less than 10 %. The method's sustainability was validated with a whiteness score of 98.8, an AGREE score of 0.64, a BAGI score of 70 and ComplexMoGAPI score of 77. Applicability was demonstrated through successful analysis of real postmortem blood samples and proficiency testing samples, highlighting its potential utility in forensic toxicology. [ABSTRACT FROM AUTHOR]

In the present work, a freshness indicator was developed by immobilizing extracted betacyanins from prickly pear fruit (PFB) onto cellulose filter paper to visually determine fish spoilage. Various properties of the prepared indicator, including color stability, moisture uptake, sensivity to hydrogen sulfide (H 2 S) gas and pH changes, and chemical analysis were studied. The PFB-based indicator exhibited good color stability at various temperatures and times, with no significan color changes observed during storage at 25, 4, and −18 °C for 8 days. The moisture absorption of the indicator based on PFB was lower than that of cellulose paper, which is crucial for colorimetric indicators. Basic nitrogen and sulfur compounds are the main volatile compounds produced during fish spoilage. The results of the present study showed that both total volatile basic nitrogen (TVB-N) and H 2 S gas produced during fish spoilage contributed to the color changes of betacyanin-based colorimetric indicators. The prepared freshness indicators were pH-sensitive, with significant color changes due to TVB-N and H 2 S production during fish storage. A significant correlation was observed between fish quality (pH, TVB-N and total viable count) and the visible color changes of the indicators. The color of the designed indicator shifted from dark pink to pale pink/white during fish storage. These prepared freshness indicators were inexpensive, easy to use, and non-toxic, making them suitable for assessing the quality and shelf life of fish fillets. • A freshness indicator was prepared based on prickly pear fruit betacyanins using cellulose paper. • The prepared indicator was sensitive to not only TVB-N but also H 2 S compounds. • A significant correlation was observed between fish quality and visible color changes. • The prepared indicator is low-cost and efficient for spoilage detection of protein-rich foods. [ABSTRACT FROM AUTHOR]

There is a need to develop low-cost, reliable and portable devices to enhance the efficiency of microextraction techniques in complex samples. Metal-organic frameworks (MOFs) have proven to be promising sorbents due to their well-documented properties. However, their green preparation and combination with paper-based substrates have not been satisfactorily explored to fabricate sustainable sorptive phases. In this work, the hybridization of a paper substrate (as a sustainable support) with MOFs (as a sorptive phase) was carried out by one-pot approach. Concretely, the selected MOF, MIL-53(Al), was in-situ growth onto the paper surface in aqueous solution without the need for high temperature or pressure, thereby aligning with the Green Analytical Chemistry principles. The optimized composite (MIL-53(Al)@cellulose paper) was characterized and evaluated as extraction sorbent for five neonicotinoids (NEOs) (thiamethoxam, clothianidin, imidacloprid, acetamiprid, and thiacloprid). Furthermore, its feasibility was demonstrated by isolating these pollutants from environmental water samples, followed their determination by HPLC coupled to diode array detection. The whole method showed satisfactory analytical performance with recoveries between 86 and 114 %, suitable precision (with RSD lower than 14 %), and limits of detection ranged from 1.0 to 1.6 μg L−1. Besides, the greenness of the method was assessed by application of different existing metrics. The developed extraction device was affordable (<0.08 €/device) and mechanical and chemically stable, being possible its reuse more than 11 cycles, thus demonstrating its suitability for rapid screening of pesticides in environmental samples. This report presents, for the first time, the green synthesis of MIL-53(Al)cellulose paper composite and its application as a sorptive phase for the extraction of NEOs from environmental water samples. We believe that the proposed strategy for fabricating these sustainable paper-based sorptive phases paves the way for further hybridizations with other MOFs or materials. Additionally, it opens up large possibilities for their application in extraction of pollutants or other hazardous compounds in aquatic environments. [Display omitted] • A novel MOF@cellulose paper-based device has been developed. • Sustainable analytical method using green MOF synthesis, paper support and microextraction. • Cost-effective, user-friendly, reproducible and reusable extraction unit. • The sorptive phase combined with HPLC-DAD provided low LODs and satisfactory recoveries. • The method was successfully applied to the analysis of NEOs in water samples. [ABSTRACT FROM AUTHOR]

This paper presents an innovative application of chitosan material to be used as pH-responsive valves for the precise control of lateral flow in microfluidic paper-based analytical devices (μPADs). The fabrication of μPADs involved wax printing, while pH-responsive valves were created using a solution of chitosan in acetic acid. The valve-forming solution was applied, and ready when dry; by exposure to acidic solutions, the valve opens. Remarkably, the valves exhibited excellent compatibility with alkaline, neutral, and acidic solutions with a pH higher than 4. The valve opening process had no impact on the flow rate and colorimetric analysis. The potential of chitosan valves used for flow control was demonstrated for μPADs employed for nitrate determination. Valves were used to increase the conversion time of nitrate to nitrite, which was further analyzed using the Griess reaction. The μPAD showed a linear response in the concentration range of 10–100 μmol L−1, with a detection limit of 5.4 μmol L−1. As a proof of concept, the assay was successfully applied to detect nitrate levels in water samples from artificial lakes of recreational parks. For analyses that require controlled kinetics and involve multiple sequential steps, the use of chitosan pH-responsive valves in μPADs is extremely valuable. This breakthrough holds great potential for the development of simple and high-impact microfluidic platforms that can cater to a wide range of analytical chemistry applications. [Display omitted] • The development of pH-responsive valves offers a simple fabrication method and operational advantage in paper-based devices. • Control over the chitosan valve is achieved by adjusting the proton concentration using acid solutions • Chitosan is a biocompatible material for constructing valves, enabling precise control over nitrate reduction • A proof-of-concept study using urban park water analysis demonstrates the effectiveness of chitosan valves. [ABSTRACT FROM AUTHOR]

The rapid development of micro-solid phase extraction (μ-SPE) procedures with new sorption materials, in particular, based on using natural materials, is currently reported. The production of these sorbents and the entire extraction procedure should support the implementation of Green Analytical Chemistry (GAC) principles. Promising materials are sorbents based on paper, which can be relatively easily modified, among others: by covering it with a polymer membrane. In this work, the practical application of paper-supported polystyrene used in the analysis of urine samples containing selected date-rape drugs (DRD) substances, and evaluation of the entire procedure using GAC metrics is presented. The paper-supported polystyrene membranes were successfully fabricated and characterized. The successful polystyrene coating on the paper was confirmed through ATR-FTIR measurements, ensuring even coverage. The μ-SPE procedure using this material facilitated extraction with a throughput of approximately 120 samples per hour in just a few steps. Throughout the research, a mixture of 100 mM acetic acid:methanol:acetonitrile (70:15:15, v/v/v) was selected as an optimal background electrolyte for capillary electrophoresis – mass spectrometry analysis. Validation results of this method demonstrated its suitability, exhibiting good linearity (R2 > 0.95), low limits of detection (3.1–15 ng mL−1), acceptable precision (<15 %), and recovery for all tested analytes. Furthermore, the greenness evaluation conducted with six different metrics: AGREEprep, AGREE, ComplexGAPI, SPMS, hexagonal metric, and WAC indicated the overall eco-friendliness and sustainability of the method, with minor concerns regarding energy consumption. The use of cellulose paper with polystyrene membranes for μ-SPE provides a versatile and eco-friendly extraction method for detecting DRDs in urine samples. The presented work is an example of the use of GAC metrics in the evaluation of the analytical procedure. The optimized PT-μ-SPE/CE–MS method allows for minimized reagent usage and waste production. Moreover, the method proves to be sustainable and efficient for forensic toxicology analysis. [Display omitted] • Utilizes a paper-supported polystyrene membrane for green micro-scale extraction. • A rapid micro-extraction method for multi analysis of DRD in urine samples. • Development of a comprehensive analytical procedure for determining DRD using the CE-MS technique. • Uses of metrics for evaluation of greenness of the analytical process. [ABSTRACT FROM AUTHOR]

This document is an exclusive review of catalytic materials and their applications in various fields. It includes reviews on topics such as enzyme-nanoparticle immobilization for biocatalysis, the catalytic activity of gold enzymes, nickel single-atom catalysts for hydrogenation and dehydrogenation reactions, heterogeneous catalysts for oxime hydrogenation, advanced oxidation processes for water and air purification, and selective catalytic reduction technology for reducing NOx emissions from diesel engines. The reviews provide insights into the synthesis, structure, and application of different catalytic materials, highlighting their potential in solving technological challenges in sensing, catalysis, and biomedicine. [Extracted from the article]

[Display omitted] • The aim of this study was to develop an eco-friendly flexible SERS substrate. • Achieving an in-situ reduction of AgNO 3 to Ag NPs on paper without any additional chemical reducing agents. • The aim of this study was to develop an eco-friendly flexible surface-enhanced Raman scattering (SERS) substrate. Over the past few decades, green analytical chemistry has gradually gained prominence worldwide due to its economic, low toxicity, and environmentally friendly characteristics. The aim of this study was to develop an eco-friendly flexible surface-enhanced Raman scattering (SERS) substrate for in situ detection of thiabendazole (TBZ). We take advantage of the reduction ability of office paper itself, achieving an in-situ reduction of AgNO 3 to silver nanoparticles (Ag NPs) on paper without any additional chemical reducing agents. The investigation of the underlying mechanism reveals that aldehydes dissolved in paper play an important role in the reduction process. Reaction time, the concentration of AgNO 3 , and the heating temperature were optimized to achieve the best SERS performance. The prepared SERS paper had high SERS activity, good reproducibility, and stability, which was evaluated by the detection of model molecules R6G and MB. Finally, the as-prepared substrate was successfully applied to detect the TBZ residue on the surface of the apple based on a wipe sampling method. The results showed that the detection limit of TBZ was 0.097 ppm and the recoveries of TBZ in actual samples range from 91.5 % to 99.7 %. Therefore, this study could provide a new way for the green synthesis of paper-based SERS substrate to detect contaminants in fruits. [ABSTRACT FROM AUTHOR]

In this research work, a coated paper was prepared with poly (butylene adipate-co-terephthalate) (PBAT) film to explore its use in eco-friendly food packaging. The paper was coated with PBAT film for packaging using hot pressing, a production method currently employed in the packaging industry. The coated papers were evaluated for their structural, mechanical, thermal, and barrier properties. The structural morphology and chemical analysis of the coated paper confirmed the consistent formation of PBAT bi-layered on paper surfaces. Surface coating with PBAT film increased the water resistance of the paper samples, as demonstrated by tests of barrier characteristics, including the water vapor transmission rate (WVTR), oxygen transmission rate (OTR), and water contact angle (WCA) of water drops. The transmission rate of the clean paper was 2010.40 cc m−2 per 24 h for OTR and 110.24 g m−2 per 24 h for WVTR. If the PBAT-film was coated, the value decreased to 91.79 g m−2 per 24 h and 992.86 cc m−2 per 24 h. The hydrophobic nature of PBAT, confirmed by WCA measurements, contributed to the enhanced water resistance of PBAT-coated paper. This result presents an improved PBAT-coated paper material, eliminating the need for adhesives and allowing for the fabrication of bi-layered packaging. [ABSTRACT FROM AUTHOR]

The impact of food contaminants on ecosystems and human health has attracted widespread global attention, and there is an urgent need to develop reliable food safety detection methods. Recently, carbon dots (CDs) have been considered as a powerful material to construct sensors for chemical analysis. Based on the concept of resource conversion and sustainable development, the use of natural, harmless, and renewable materials for the preparation of CDs without the involvement of chemical hazards is a current hot topic. This paper reviews the research progress of green-derived CDs and their application in food safety biosensing. The fabrications of green-derived CDs using various biomasses are described in detail, and the application of CDs especially the sensing mechanisms of photoluminescence, colorimetric, electrochemiluminescence and other sensors are provided. Finally, existing shortcomings and current challenges as well as prospects for food safety monitoring are discussed. We believe that this work provides strong insight into the application of CDs in the sensing of various contaminants. [ABSTRACT FROM AUTHOR]

The applications of various clay minerals are related to their structural, physical, and chemical characteristics. These properties of the clay minerals dictate their utilization in the industries and beneficiation required before usage. The study aimed at establishing the potentiality of acid‐activated clay mineral from Hadar, Afar, Ethiopia. XRD, SEM, energy‐dispersive X‐ray fluorescence (EDXRF), and FT‐IR spectroscopies were employed to characterize the chemical compositions and interaction in the bentonite samples. The XRD results revealed that the native and activated bentonite clay contains similar minerals, such as montmorillonite (MMT) ([Ca, Na]0.33 [Al, Mg]2[Si4O10][OH]2.nH2O), quartz (SiO2), albite (NaAl2SiO6), zeolite (CaAl2O3.SiO2.nH2O), and aluminum silicate. Thus, attributes of the bentonite clay was composed of SiO2 and Al2O3 indicating that it is an aluminosilicate mineral, and the morphology of bentonite was supported by SEM. The chemical analysis by EDXRF revealed that the native bentonite (NB) consisting of 58.18 wt% (SiO2), 14.28 wt% (Al2O3), and Na2O > CaO are the major constituents of the clay with other oxides present in low amount. There was an increase in the SiO2 content in activated bentonites, and the Al2O3, Fe2O3, and MgO contents have decreased by 48.56%, 66.36%, and 84.42%, respectively. The FT‐IR spectra bands at 1627 cm−1 and 1027 cm−1 were attributed to Al–Mg–OH, Al–Al–OH, and Al–OH–O–Si stretching vibration, and the reduction of the content of the octahedral cations is accompanied by a decrease of both OH bending vibrations at 1627 and 3401 cm−1. The FT‐IR result is in clear agreement with the SEM, XRD, and EDXRF studies which indicate sequential degradation of the clay sheet upon acid treatment. Hence, rendering the activated bentonite clay of Hadar has accounted for their demand for different industrial applications such as its use as detoxifier, sealant, binder, fillers for paper, pharmaceutical products, absorbent, adsorbent, catalyst, and nanoclays. [ABSTRACT FROM AUTHOR]

Food contact paperboard poses a potential risk of food contamination due to the possible release of chemicals (intentionally added or not), particularly in recycled paperboard. Water extractions were performed, according to wet food procedures, of paperboard samples collected from a manufacturer at the beginning and the end of a recycling production chain. Chemical analysis and hormonal activities in vitro of water extracts were studied. ICP–MS analysis confirmed the presence of 15 trace elements with lower concentrations after the recycling process, with the exception of chlorine. The chromatographic analyses demonstrated that the identified substances in the starting paperboard, before the recycling process, were approximately twice as high as in the end paperboard, after the recycling process. These substances included also natural wood products, chemical additives, and undesirable substances such as phthalates. Two major products (3,5-di-tert-butylphenol and methyl-2-pyrrolidone) were found in the starting and the end paperboard extracts, respectively. Two common substances were identified in both extracts: 2,4-di-tert-buthylphenol and dehydroabietic acid. Evaluation of potential endocrine disruption showed that the starting paperboard extract exhibited oestrogenic and antiandrogenic effects, while these effects nearly disappeared in the end paperboard extract. These results confirmed that the recycling process was effective in removing most of the contaminant substances. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry," published by The Royal Society of Chemistry. It features articles and papers on various topics, including synthetic routes and chemical structural analysis for new Pt(II) metallodrug design and the synthesis and reactivity of air stable Ni(II) complexes. The correction notice in the document acknowledges an error in the original publication of a study on the reactivity of a Lewis superacidic carborane-based compound towards Lewis bases, authored by Libo Xiang, Alexander Matler, Leibo Tan, and Qing Ye. The notice provides the correct page number for the article. [Extracted from the article]

Small molecules find extensive application in medicine, food safety, and environmental studies, particularly in biomedicine. Immunoassay technology, leveraging the specific recognition between antigens and antibodies, offers a superior alternative to traditional physical and chemical analysis methods. This approach allows for the rapid and accurate detection of small molecular compounds, owing to its high sensitivity, specificity, and swift analytical capabilities. However, small molecular compounds often struggle to effectively stimulate an immune response due to their low molecular weight, weak antigenicity, and limited antigenic epitopes. To overcome this, coupling small molecule compounds with macromolecular carriers to form complete antigens is typically required to induce specific antibodies in animals. Consequently, the preparation of small-molecule artificial antigens and the production of efficient specific antibodies are crucial for achieving precise immunoassays. This paper reviews recent advancements in small molecule antibody preparation technology, emphasizing the design and synthesis of haptens, the coupling of haptens with carriers, the purification and identification of artificial antigens, and the preparation of specific antibodies. Additionally, it evaluates the current technological shortcomings and limitations while projecting future trends in artificial antigen synthesis and antibody preparation technology. [ABSTRACT FROM AUTHOR]

The immense popularity of coffee around the world generates significant amounts of coffee grounds. They are often improperly disposed of, which can have a negative impact on the environment. Due to their chemical composition and physical properties, coffee grounds are an excellent bioenergy material. This paper presents a study of the feasibility of using spent coffee grounds (CG) as an additive to pine sawdust (PS) pellets to improve their energy properties. The tests were carried out on samples of pellets consisting of 100% PS, 100% CG, and mixtures of 95% PS and 5% CG, 85% PS and 15% CG, and 70% PS and 30% CG. Physical and chemical analyses were carried out to determine the suitability of the obtained pellet as a biofuel in accordance with ISO 17225. Combustion tests were also carried out in a laboratory boiler to analyze flue gases and determine CO and NOx emissions in accordance with EN-303-5 for biomass boilers. The amount of emitted volatile organic compounds (VOCs) was also determined. Experimental results show that the addition of CG to PS reduces the durability of the pellets and increases CO and NOx emissions but increases their energy value and reduces the amount of VOC emissions. The requirements of both standards were fulfilled with a mixture of 95% PS and 5% CG. However, test results show that it is possible to add CG to PS in amounts up to 15%, although this will require additional research. [ABSTRACT FROM AUTHOR]

Spectral multivariate calibration aims to derive models characterizing mathematical relationships between sample analyte amounts and corresponding spectral responses. These models are effective at predicting target domain sample analyte amounts when target samples are within the analyte and spectral calibration source domain. Models fail when target samples shift (analyte amounts and/or spectra) from the original calibration domain model. A total recalibration solution requires acquisition of new sample reference values and spectra. However, obtaining enough reference values to distinguish the target domain may be challenging or expensive. A simpler approach adapts the original model to the target domain using target sample spectra without analyte reference values (unlabeled). Analytical chemists have developed several machine learning algorithms using unlabeled regression domain adaptation processes. Unfortunately, prediction accuracy declines for these methods depending on how much the target domain analyte distribution has shifted from the calibration distribution, and regression transfer learning methods are instead needed. Regression domain adaptation and transfer learning are often referred to as model updating in analytical chemistry, but regression domain adaptation only applies to spectral shifts. The regression transfer learning method presented in this paper named null augmentation regression constant analyte (NARCA) leverages unlabeled repeat spectra of a single target sample to update an original calibration model to the shifted target domain sample. With sample repeat spectra, the analyte amount can be assumed constant or nearly constant for NARCA and because models are formed for one sample, NARCA operates as a local modeling method. The performance of NARCA as a regression transfer learning method is evaluated using five near-infrared data sets. [ABSTRACT FROM AUTHOR]

Mole fraction solubilities are reported for (2-nitrophenyl)acetic acid dissolved in 1-pentanol, 1-heptanol, 1-octanol, 2-butanol, 3-methyl-1-butanol, 2-pentanol, 4-methyl-2-pentanol, cyclopentanol, 2-ethoxyethanol, 2-propoxyethanol, 2-isopropoxyethanol, 1,4-dioxane, methyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, tert-butyl acetate, pentyl acetate, methyl butyrate, dimethyl adipate and propanenitrile at 298.15 K. Solubilities were determined using a spectrophotometric method of chemical analysis. Experiment-based Abraham model solute descriptors are calculated for the molecular, monomeric form of (2-nitrophenyl)acetic acid by combining our experimental values with the published solubility data obtained from the published paper by Zhou and co-workers. The calculated solute descriptors describe the observed solubility data to within an overall standard deviation of 0.10 log units. [ABSTRACT FROM AUTHOR]

Graph theory is used in many areas of chemical sciences, especially in molecular chemistry. It is particularly useful in the structural analysis of chemical compounds and in modeling chemical reactions. One of its applications concerns determining the structural formula of a chemical compound. This can be modeled as a variant of the well-known graph realization problem. In the classical version of the problem, a sequence of natural numbers is given, and the question is whether there exists a graph in which the vertices have degrees equal to the given numbers. In the variant considered in this paper, instead of a sequence of natural numbers, a sequence of sets of natural numbers is given, and the question is whether there exists a multigraph such that each of its vertices has a degree equal to a number from one of the sets. This variant of the graph realization problem matches the nature of the problem of determining the structural formula of a chemical compound better than other variants considered in the literature. We propose a polynomial time exact algorithm solving this variant of the problem. [ABSTRACT FROM AUTHOR]

Spinel group minerals, found within various rock types, exhibit distinct categorizations based on their host rocks. According to Barnes and Roeder (2001), these minerals can be classified into eight primary groups, each further subdivided into variable numbers of subgroups that can be related to a particular tectonic setting. This classification is based on the cations corresponding to the end-members of the spinel prism and is traditionally analyzed in this prismatic space or using projections of it. In this prismatic representation, several categories tend to overlap, making it impossible to determine which is the tectonic environment in that scenario. An alternative to solve this problem is to generate representations of these groups considering more attributes, making the most of the many values measured during the geochemical analysis. In this paper, we present SpinelVA, a visual exploration tool that integrates Machine Learning techniques and allows the identification of groups using the cations considered by Barnes and Roeder and some additional ones obtained from chemical analysis. SpinelVA allows us to know the tectonic environment of unknown samples by categorizing them according to the Barnes and Roeder classification. Additionally, SpinelVA integrates a collection of visual analysis techniques alongside the already used spinel prism projections and provides a set of interactions that assist geologists in the exploration process. Users can perform a complete data analysis by combining the proposed techniques and associated interactions. [ABSTRACT FROM AUTHOR]

A first-class curriculum stands at the heart of talent education, playing a pivotal role in achieving the educational objectives. Against the backdrop of the “Double Frist-Class” initiative, this paper examines the construction approach and practices of the provincial-level premier course in Inorganic and Analytical Chemistry at Jianghan University. Educational reforms have been implemented in three key areas: the integration of professional and ideological education, consolidation of teaching content and resources, and the blending of online and offline instructional methods. This has led to the development of a “MOOCs + Flipped Classroom + Problem-Based-Learning (PBL)” instructional model and a “Three-Phase, Seven-Step” teaching methodology, both aimed at enhancing students’ engagement and fostering their self-directed learning skills. These measures offer valuable insights for the development of Inorganic and Analytical Chemistry courses at local colleges and universities. [ABSTRACT FROM AUTHOR]

Simple Summary: In forensic entomology, insects are used to estimate the time since death and to answer other investigative questions, such as determining if the body was moved postmortem or identifying the season of death. In funerary archeoentomology, insects provide information related to the season of death, body transfer, and funerary practices. To obtain this information, the correct identification of specimens collected from the scene is fundamental. In old cases and archeological contexts, the majority of entomological evidence samples found are fly puparia, barrel-like structures formed from the third-instar larval cuticle where metamorphosis takes place. Despite recent publications of identification keys for certain fly larvae and adults, there is still a lack of tools for puparium identification. This problem is exacerbated by the scarcity of diagnostic features present on the puparia. This paper critically reviews the techniques available for puparium identification in addition to traditional morphological analysis. It describes DNA-based approaches and chemical analyses of cuticular lipids and hydrocarbons, highlighting the importance of using non-invasive methods to guarantee the repeatability of the analysis—a key element in forensic science—or to preserve precious and unique specimens from museum collections. Diptera identification is fundamental in forensic entomology as well as in funerary archeoentomology, where the challenge is exacerbated by the presence of immature stages such as larvae and puparia. In these two developmental stages, specimens possess a very limited number of diagnostic features, and for puparia, there is also a lack of identification tools such as descriptions and identification keys. Morphological analysis, DNA-based techniques, and cuticular chemical analyses all show good potential for species identification; however, they also have some limitations. DNA-based identification is primarily hindered by the incompleteness of genetic databases and the presence of PCR inhibitors often co-extracted from the puparial cuticle. Chemical analysis of the cuticle is showing promising results, but this approach is also limited by the insufficient profile database and requires specific, expensive equipment, as well as trained personnel. Additionally, to ensure the repeatability of the analysis—a critical aspect in forensic investigations—and to preserve precious and unique specimens from museum collections, non-invasive protocols and techniques must be prioritized for species identification. [ABSTRACT FROM AUTHOR]

Recent increase in curiosity regarding behavior of two-dimensional layered materials leads the scientists worldwide to explore various physico-chemical properties of these materials. Promising application of MoS2 as electrode material for various electrochemical devices prompted our group to investigate and compare the electrochemical nature of bare glassy carbon electrode with that of PANI/ MoS2 modified glassy carbon electrode. PANI is preferred over other materials in electrochemical applications owing to its unique properties as conductive polymer. In this paper, a comparison of the voltammetric response of dopamine has been explored on both the electrodes. The study indicates that the voltammetric response is slightly better in case of modified glassy carbon electrode in comparison to bare electrode. Study also shows that the effect of adsorption is also observable on both the electrodes from concentration of 0.4 µM onwards. The outcome of this paper holds significant implications for a wide range of electroanalytical applications, biomedical sensing and other chemical analysis. [ABSTRACT FROM AUTHOR]

Lead-based perovskites are highly susceptible to environmental influences, and their application in analytical chemistry, especially in aqueous solution, has been reported rarely. All-inorganic lead-free metal halide perovskites have been considered as a substitute for lead-based perovskites. Herein, a Cs2RbTbCl6 perovskite microcrystal (PMCs), which emits strong yellow-green fluorescence with a maximum emission wavelength at 547 nm, was for the first time synthesized and characterized. The Cs2RbTbCl6 PMCs could be well dispersed in N,N-dimethylacetamide (DMF), and its fluorescence could be significantly enhanced by the addition of norfloxacin (NOR) in the aqueous solution. We found that the Cs2RbTbCl6 PMCs can be used as fluorescent probes (excitation, 365 nm; emission, 547 nm) to selectively detect NOR in a concentration range from 10.0 to 200.0 μM with the limit of detection (LOD) being 0.04 μM. The Cs2RbTbCl6 PMCs could also be adsorbed on filter paper to fabricate as a fluorescent test paper for visual detection of NOR under 365-nm ultraviolet (UV) lamp irradiation. The proposed method has the potential to establish a new analytical method to visualize the detection of NOR in aqueous environments and also promotes the application of all-inorganic lead-free perovskites for analytical detection in aqueous environments. [ABSTRACT FROM AUTHOR]

Bioactive substances that can prevent the growth of pathogenic germs can be produced by endophytic bacteria This study aims to identify seaweed endophytic bacteria (Turbinaria ornata, Sargassum crassifolium, Sargassum polycystum) and their potential antibacterial activity against skin disease agents (Staphylococcus aureus and Staphylococcus epidermidis). In February 2023 (the rainy season), seaweed was harvested from the waters off Panjang Island in Jepara Regency, Central Java, Indonesia. Endophytic bacterial isolates that had been effectively isolated and purified were directly tested for antibacterial activity. Three isolates with the best antibacterial activity were extracted using the ethyl acetate solvent. The extract samples will be put through additional antibacterial testing using the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and paper disc diffusion procedures. Using the thin layer chromatography (TLC), the class of chemical components in the extract was determined. A molecular technique based on the 16s rRNA gene (1,400 bp) was used to identify endophytic bacterial isolates. Three species of seaweed yielded 25 isolates of endophytic bacteria: 11 from T. ornata, 7 from S. crassifolium, and 7 from S. polycystum. To.09.pp, To.10.pp, and Sc.06.pp were the 3 isolates with the highest antibacterial activity in the direct challenge test. Zone of inhibition results from subsequent antibacterial testing using paper disc diffusion ranged from medium to very strong intensity. To.10.pp sample's MIC test yielded the best results, with S. aureus and S. epidermidis concentrations of 937.5 and 1,875 µg/mL, respectively. MBC test yielded the highest findings, with S. aureus and S. epidermidis concentrations of 1,875 and 1,875 µg/mL, respectively. The To.10.pp sample yielded terpenoids, alkaloids, and flavonoids, according to TLC analysis of chemical constituent groups. Acinetobacter indicus strain 80-1-2 and Vibrio harveyi strain B14-1 were identified as potential endophytic bacteria from T. ornata, and Acinetobacter indicus strain 80-1-2 from S. crassifolium. [ABSTRACT FROM AUTHOR]

The swift advancement of heat transfer technologies can be attributed to the growing need for effective heating and cooling systems in various sectors, including the automotive, chemical, and aerospace industries. This work aims to examine the impact of radiation on the behavior of Casson hybrid nanoparticles (Al2O3-CuO) mixed convective flow in three distinct scenarios. The physical properties of copper oxide (CuO) and aluminum oxide (Al2O3) nanoparticles are utilized when mixed with CMC-water as the solvent. This paper aims to analyze the influence of mixed convective flow on the thermal integrity of hybrid nanoparticles when subjected to a wedge, cone, and plate. The analysis of chemical reactions and the existence of a permeable substance is also incorporated. The partial differential systems are appropriately transformed into a system of ordinary differential equations (ODEs). In addition, the calculation of this system of ODEs is carried out using the analytical technique known as the homotopy analysis approach (HAM). The study examines potential resolutions for flow issues in three distinct configurations: wedge, cone, and plate. A comprehensive examination and record of the impacts of various physical characteristics is carried out. The concepts of wall friction, Nusselt number, and Sherwood number, among others, are explained through the utilization of graphical representations. The porosity and Casson fluid characteristics cause a decrease in the performance of the velocity profile. Hybrid nanofluids have superior heat transfer efficiency compared to conventional nanofluids. [ABSTRACT FROM AUTHOR]

The goal of this probing is to scrutinize the impact of chemical reaction and radiation on the flow behavior of a nanofluid, made up of copper nanoparticles suspended in water, as it moves through a vertically oscillating plate in a magnetohydrodynamic free, unsteady convective system. We tackled the problem with a mathematical model incorporating nanoparticle volume fraction and used a closed-form Laplace transformation method to resolve the governing equations for momentum, energy, and concentration field. The results were also depicted graphically with heat transport rate, mass transport rate, and skin friction illustrations. The study shows that increasing the volume fraction of Cu–water-based nanoparticles decreases primary and secondary velocities, while the temperature field grows. Moreover, a higher chemical reaction parameter leads to a drop in the fluid concentration. Furthermore, a graphic representation of the upshots of variant dimensionless parameters on the nanofluid velocity, temperature, and species concentration is provided. The subject of this paper explores an extension that involves the inclusion of Cu–water-based nanofluid. This nanofluid exhibits significantly higher thermal conductivity compared to typical fluids. Consequently, it can be considered a superior alternative to conventional fluids, proving to be valuable in enhancing heat transfer in diverse engineering and industrial processes. This study is significantly relevant to various industrial and machine-building applications. [ABSTRACT FROM AUTHOR]

This study presents research into the unique method of depositing carbon layers onto processed surfaces, during finishing with abrasive films, on a global basis. The authors of this article are holders of the patent for this method. What makes this technology outstanding is that it integrates processes, whereby micro-finishing and the deposition of a carbon layer onto freshly exposed surface fragments is achieved simultaneously, in a single process. Among the main advantages accruable from this process is the reduction of surface irregularities, while the deposition of a carbon layer is achieved simultaneously. Ultrathin graphite layers can be widely used in conditions where other methods of reducing the coefficient of friction are not possible, such as in regard to micromechanisms. This article illustrates the application of carbon coating, end on, on a surface processed with abrasive film, containing intergranular spaces, saturated with graphite. Thin carbon layers were obtained on two substrates that did not contain carbon in their initial composition: soda–lime glass and a tin–bronze alloy. It was performed through microscopic examinations of the produced surface, roughness analyses of these surfaces, and analysis of the chemical compositions determined by two methods, namely EDS and GDOES, proving the existence of the coatings. The aim of this paper is to prove the possibility and efficiency of using graphite-impregnated lapping films in the deposition process of carbon films, with improved surface smoothness, durability, and wear resistance. The produced coatings will be tested in regard to their operational properties in further research. The authors underline the potential of this method to revolutionize surface treatment processes, due to the significant advantages it offers across various industries. [ABSTRACT FROM AUTHOR]

Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful tools in analytical chemistry. An important step in the analysis of NMR data is the assignment of resonance frequencies to the corresponding atoms in the molecule being investigated. The traditional approach considers the spectrum's characteristic parameters: chemical shift values, internuclear couplings, and peak intensities. In this paper, we show how to support the process of assigning a series of spectra of similar organic compounds by using temperature coefficients, that is, the rates of change in chemical shift values associated with given changes in temperature. [ABSTRACT FROM AUTHOR]

The need for elemental analysis in quality control of food, pharmaceuticals and cosmetics, taking into account human safety, has become an essential requirement for any product destinated for commercialization and targets in particular potentially toxic elements. The main objective is to obtain reliable data on elemental content that enables end-users to make informed decisions and to address problems effectively. To align with the principles of green and sustainable analytical chemistry, recent efforts have focused on incorporating new, low-cost screening and quantitative analytical tools such as total reflection X-ray fluorescence spectrometry (TXRF). This paper provides an overview of recent TXRF applications in the elemental analysis of food, pharmaceuticals, and cosmetic samples. The state-of-the-art procedures for sample preparation with details on the sample type and amount, dilution steps, mixing agents, analysed elements, and addition of internal calibration standards are presented together with analytical parameters such as limits of detection and quantification. The current challenges for applying TXRF to each of these research fields are discussed. [ABSTRACT FROM AUTHOR]

The dispersive liquid-liquid microextraction (DLLME) is one of the most popular miniaturized extraction procedures. In this paper, the degree of dispersion and dispersion stability were studied with the aim to assess the correlations of these parameters with efficiency for the selected analytical application. The dependence between the degree of dispersion (cloudy state quality) and its stability obtained by various emulsification procedures, such as solvent-assisted emulsification (using various dispersive solvents) and mechanical emulsification (using auxiliary energies), is investigated and discussed. It was found out that the degree of dispersion depends on the type of emulsification procedure and decreases in the series: solvent-assisted (SA-) = ultrasound-assisted (UA-) > air-assisted (AA-) > vortex-assisted (VA-) emulsification. The emulsion stability depends on the degree of dispersion and there were 1810 and 2070 s for the most effective emulsification procedures, such us solvent-assisted and ultrasound-assisted emulsification, respectively. A comparison between the sensitivity of the analytical methods (using spectrophotometric determination of the anionic surfactants) and the degree of dispersion have been made. The sensitivity of the methods was ranked as follows: DLLME > UA-LLME > VA-LLME > AA-LLME. [ABSTRACT FROM AUTHOR]

Hydroxyl‐terminated polybutadiene (HTPB) is hydrogenated using catalytic hydrogenation with HTPB as a precursor using various catalysts. The hydrogenation is carried out using iso‐propyl alcohol (IPA) and toluene as an active solvent media. The present paper used (a) charcoal, (b) palladium supported by charcoal (Pd−C), (c) palladium supported by zirconium oxide (Pd‐ZrO2), and (d) copper chromite (CC) as catalysts for hydrogenation of HTPB to study the influence on the degree of hydrogenation with respect to each catalyst. The experimental data shows that hydrogenated HTPB (HHTPB) formation is predominantly controlled by physisorption and chemical reaction with a catalyst. Various techniques like NMR, FTIR and chemical analysis are used to characterize HTPB and HHTPB. Degree of hydrogenation of HTPB is found to be higher with copper chromite when compared to other catalysts in this work. Post‐hydrogenation, no significant change in hydroxyl value and a marginal increase in molecular weight is noticed with all catalysts. HTPB and HHTPB samples are analyzed using FTIR, 1H‐NMR, and 13C‐NMR and TG‐DSC studies, and inferences are derived with respect to the change in the olefinic region, microstructural changes, molecular weight, and thermal decomposition characteristics. [ABSTRACT FROM AUTHOR]

Addressing the challenges inherent in the traditional teaching mode of analytical chemistry course, this paper takes the initiative under the concept of course ideology and politics to implement educational reforms. It outlines a comprehensive strategy for the ideological and political development within the analytical chemistry curriculum. These reforms encompass a broad range of areas, including the revision of the teaching syllabus, the reconstruction of teaching content, the transformation of teaching methodologies, and the overhaul of course assessment methods. By integrating online and offline blended teaching methods, this reform synchronizes the value-driven guidance provided by instructors with the deep engagement of students, achieving a holistic educational objective that encompasses knowledge transmission, ability cultivation, and value shaping. [ABSTRACT FROM AUTHOR]

Three decades after A. P. de Silva's seminal paper introduced the concept of logic gates at the molecular level, the field of molecular logic gates (MLGs) has witnessed significant advancements. MLGs are devices designed to perform logical operations, utilizing one or more physical or chemical stimulus signals (inputs) to generate an output response. Notably, MLGs have found diverse applications, with optical detection of analytes emerging as a notable evolution of traditional chemosensors. Organic synthesis methods are pivotal in crafting molecular architectures tailored as optical devices capable of analyte detection through logical functions. This review delves into the fundamental aspects and physical–chemical properties of MLGs, with a particular emphasis on synthetic strategies driving their design. [ABSTRACT FROM AUTHOR]

An important application of CRISPR interference (CRISPRi) technology is for identifying chemical-genetic interactions (CGIs). Discovery of genes that interact with exposure to antibiotics can yield insights to drug targets and mechanisms of action or resistance. The objective is to identify CRISPRi mutants whose relative abundance is suppressed (or enriched) in the presence of a drug when the target protein is depleted, reflecting synergistic behavior. Different sgRNAs for a given target can induce a wide range of protein depletion and differential effects on growth rate. The effect of sgRNA strength can be partially predicted based on sequence features. However, the actual growth phenotype depends on the sensitivity of cells to depletion of the target protein. For essential genes, sgRNA efficiency can be empirically measured by quantifying effects on growth rate. We observe that the most efficient sgRNAs are not always optimal for detecting synergies with drugs. sgRNA efficiency interacts in a non-linear way with drug sensitivity, producing an effect where the concentration-dependence is maximized for sgRNAs of intermediate strength (and less so for sgRNAs that induce too much or too little target depletion). To capture this interaction, we propose a novel statistical method called CRISPRi-DR (for Dose-Response model) that incorporates both sgRNA efficiencies and drug concentrations in a modified dose-response equation. We use CRISPRi-DR to re-analyze data from a recent CGI experiment in Mycobacterium tuberculosis to identify genes that interact with antibiotics. This approach can be generalized to non-CGI datasets, which we show via an CRISPRi dataset for E. coli growth on different carbon sources. The performance is competitive with the best of several related analytical methods. However, for noisier datasets, some of these methods generate far more significant interactions, likely including many false positives, whereas CRISPRi-DR maintains higher precision, which we observed in both empirical and simulated data. Author summary: CRISPRi technology is revolutionizing research in various areas of the life sciences, including microbiology, affording the ability to partially deplete the expression of target proteins in a specific and controlled way. Among the applications of CRISPRi, it can be used to construct large (even genome-wide) libraries of knock-down mutants for profiling antibacterial inhibitors and identifying chemical-genetic interactions (CGIs), which can yield insights on drug targets and mechanisms of action and resistance. The data generated by these experiments (i.e., sgRNA counts from high throughput sequencing) is voluminous and subject to various sources of noise. The goal of statistical analysis of such data is to identify significant CGIs, which are genes whose depletion sensitizes cells to an inhibitor. In this paper, we show how to incorporate both sgRNA efficiency and drug concentration simultaneously in a model (CRISPRi-DR) based on an extension of the classic dose-response (Hill) equation in enzymology. This model has advantages over other analytical methods for CRISPRi, which we show using empirical and simulated data. [ABSTRACT FROM AUTHOR]

Siderophores are a class of small molecules renowned for their high iron binding capacity, essential for all life forms requiring iron. This article provides a detailed review of the diverse classifications, and biosynthetic pathways of siderophores, with a particular emphasis on siderophores synthesized via nonribosomal peptide synthetase (NRPS) and non-NRPS pathways. We further explore the secretion mechanisms of siderophores in microbes and plants, and their role in regulating bioavailable iron levels. Beyond biological functions, the applications of siderophores in medicine, agriculture, and environmental sciences are extensively discussed. These applications include biological pest control, disease treatment, ecological pollution remediation, and heavy metal ion removal. Through a comprehensive analysis of the chemical properties and biological activities of siderophores, this paper demonstrates their wide prospects in scientific research and practical applications, while also highlighting current research gaps and potential future directions. [ABSTRACT FROM AUTHOR]

Annually, a tremendous amount of mercury is emitted due to anthropogenic activities. As a consequence, occupational and environmental exposure to mercury has drawn broad concern all over the world, and attempts have been sustained to progress analytical methods. The main limitation in exposure assessment is the complexity of biological and environmental samples. Environmental and biological samples need sample preparation to eliminate matrix interferences as well as pre-concentration of the ultra-trace analyte. Among sample preparation methods, considerable attention is devoted to solid-phase extraction (SPE). Porous materials play a vital role in the solid phase extraction procedure for the adsorption and desorption of the target analytes. In this paper, porous materials that were applied for inorganic mercury solid phase extraction were reviewed from 2009 until 2023. Through this study, porous materials were classified and the extraction parameters of each analytical method, including the type of solid phase extraction, porous adsorbent, adsorbent amount, extraction efficiency, real matrices, and detection technique, were clarified. Ultimately, novel attitudes toward green analytical chemistry and innovative ideas were discussed in order to open new horizons. [ABSTRACT FROM AUTHOR]

The regulation of the pyrolysis process is a key step in increasing the carbon sequestration capacity of biochar. The effect of K3PO4 addition on the yield, chemical composition, characteristic functional groups, macromolecular skeleton, graphite crystallites, and stability of biochar was studied in this paper using two-dimensional infrared correlation spectroscopy (2D-PCIS), X-ray photoelectron spectroscopy, Raman spectrum, and other characterization methods combined with thermal/chemical oxidation analysis. It is discovered that adding K3PO4 may effectively minimize the graphitization temperature range and increase biochar's yield, aromaticity, H/C ratio, and proportion of refractory/recalcitrant organic carbon. The 2D-PCIS and Raman analysis revealed that K3PO4 mostly promoted the dehydrogenation and polycondensation process of the aromatic rings in the char precursor, transforming the amorphous carbon structure of biochar into an ordered turbostratic microcrystalline structure. K3PO4 enhanced biochar stability mostly at medium-high temperatures (350 ~ 750℃) by stimulating the transformation of unstable structures of biochar to stable carbon-containing structures or by inhibiting the interaction of its active sites with oxidants through the mineralization process. A 20% phosphorus addition increased biochar's refractory index (R50) by roughly 11%, and it also boosted biochar's oxidation resistance (H2O2 or K2CrO4) efficiency, reducing carbon oxidation loss by up to 7.31%. However, at higher temperatures (> 750 ℃), the doping of phosphorus atoms into the carbon skeleton degraded the biochar structure's stability. The results of this study suggest that using exogenous phosphorus-containing additives is an efficient way to improve the stability of biochar. Highlights: K3PO4 promoted biochar precursor's dehydrogenation/polycondensation process to form fused-ring aromatic structures. K3PO4 increased recalcitrant carbon proportion and shielded biochar's active sites through the mineralization process. By adding 20 wt% of K3PO4, the thermal and chemical stability of biochar were enhanced by 11% and 7%, respectively [ABSTRACT FROM AUTHOR]

The paper proposes an overview of the primary applications of generalized two-dimensional correlation spectroscopy (2D-COS) to analytical chemistry. 2D-COS is a method used to analyze datasets obtained by spectroscopic measurements. This approach is based on the use of 2D correlation maps to detect and analyze correlations between different spectral regions or data from two measurement methods. The objective of employing 2D-COS is to enhance the volume of analytical information by uncovering latent correlations within the data. Analysis of such correlations for series of spectral data, acquired over a range of analyte concentrations, pH values, or component ratios in mixtures, and also under varying temperatures or other external factors, enables investigating and elucidating chemical processes and interactions. This information is not readily attainable directly from the spectra. In comparison to one-dimensional spectra, 2D-COS excels in the significance of analytical information, particularly in the identification of components and the determination of the composition of complex mixtures. 2D-COS can also be used for monitoring changes in a sample over time, which makes it a valuable tool for studying dynamically evolving systems. Overall, 2D-COS is a sufficiently versatile approach that can be employed in conjunction with numerous methods, addressing a wide range of analytical tasks and complex samples, also without sample preparation. The review highlights achievements in the application of 2D-COS by the beginning of September 2023. [ABSTRACT FROM AUTHOR]

NMR spectroscopy is one of the most potent methods in analytical chemistry. NMR titration experiments are particularly useful since they measure molecular binding affinities and other concentration-dependent effects. These experiments, however, require a long series of measurements. An alternative to these serial measurements has recently been presented, exploiting a pH (or generally – a concentration) gradient along the NMR tube. The proposed experiment, although efficient, was based on the sensitivity- and hardware-demanding chemical shift imaging (CSI) method. Thus, it is practically limited to high-resolution NMR spectrometers. This paper proposes modifying and adapting the approach to the popular and cost-efficient benchtop NMR machines. Instead of CSI, we use a device that shifts the NMR tube vertically to measure the spectra of different sample volumes, which have different pH values due to the established gradient along the tube. We demonstrate the potential of the method on the test samples of L -tyrosine and 2,6-lutidine, and two real samples from the food industry – an infant formula and an energy drink. The proposed method boosts spectral resolution and allows for the sampling of a broader range of pH values when compared to the original approach. [ABSTRACT FROM AUTHOR]

The chemical industry is acquiring new advancement day by day. Previously, quite massive equipment had been used to do heat transferring tasks, but now the industry has been modernised. Heat Integration is a trending area of study that might be applied in several sectors to redesign processes. Heat Integration alludes to any technique in chemical engineering that results in considerably smaller, greener, and more energy-efficient appliances. Heat Integration aims to improve energy transfer, lowering the equipment's capacity for heat transfer. This paper uses pinch analysis to optimize heat integration and find the best heat-exchange network through case studies. Pinch Technology offers a systematic approach to reducing energy use across all sites and activities. It is feasible to determine the proper alterations to the fundamental process parameters that can result in energy savings by using pinch technology. The Aspen Energy Analyzer tool has been used to compute the heat integration of the case studies. After obtaining the data from the software, they were used in pinch analysis to determine the optimal alternative for the heat exchanger network. [ABSTRACT FROM AUTHOR]

The Analytical Chemistry course focuses on quantitative analysis, emphasizing the integration of theory and practice, and the unity of knowledge and practice. To cultivate students' innovative and logical thinking skills, this paper uses the "application of acid-base titration method" as a case study. Starting from microscopic knowledge content, it constructs the logical relationships within the theoretical system. Based on this, the teaching design is developed, focusing on clarifying the knowledge framework, deeply considering logical relationships, and reconstructing course resources. Through a project-based case teaching method, the initiative and innovation of students are stimulated, enhancing the effectiveness of teaching. [ABSTRACT FROM AUTHOR]

In order to comprehensively promote the integration of ideology and politics into the curriculum, it is essential to implement teaching reforms. This paper proposes several measures to advance the ideological and political construction in the analytical chemistry curriculum, based on the characteristics of the discipline and the objectives of the course. These measures include enhancing teachers' capacity for ideological education, establishing a framework for integrating ideology and politics into the curriculum, exploring the ideological elements within the analytical chemistry course, and optimizing teaching evaluations. By integrating ideological education with professional knowledge, students can not only acquire theoretical knowledge and practical skills in analytical chemistry but also cultivate a patriotic spirit centered around core values such as reform, innovation, and scientific development. This approach aims to foster a comprehensive understanding of dialectical materialism, instill a rigorous and pragmatic scientific attitude, and promote a consensus on the significance of ideological and political education within the curriculum. Ultimately, these efforts seek to achieve a harmonious integration of teaching and moral education, facilitating the development of students' character and values. [ABSTRACT FROM AUTHOR]

Raman spectroscopy can be effectively used for detection and analysis of chemical agents that are serious threats in modern warfare, but the detection and analysis performance is prone to deterioration due to noise. The existing denoising technique has limitations that there is no criterion for selecting the window length and that the filtering distorts the peaks, key features for Raman spectral data analysis. To overcome such limitations, in this paper, we propose the peak‐aware adaptive denoising for Raman spectroscopy based on machine learning approach. The proposed technique utilizes the information of detected peaks to eliminate noise effectively using different window values optimal for each region in the Raman spectrum while preserving the shape of peaks. We conducted the various analyses and experiments, and the proposed technique showed a 28% lower Euclidean distance and a 48% lower Fréchet inception distance compared to the existing technique, meaning the proposed technique outperformed the existing one. [ABSTRACT FROM AUTHOR]

Ordinary differential equations are often employed in chemical kinetics mathematical modeling. The theoretical results for a model of a multi-step chemical kinetic process are presented in this article. This model seeks to describe both the complicated kinetics of complex chemical processes and the steady state behavior of chemical species. Reduction techniques are used to divide fast and slow processes according to their time scales, which simplifies the model. As a result, the quick processes are removed, making the slow processes the main emphasis of a reduced-dimensional model. The paper concentrates on a two-step reversible reaction mechanism for model reduction, which reduces the complexity of the entire reaction process. The phase flow of solution trajectories close to equilibrium points is also given special consideration in the analysis as it offers a clear and pertinent depiction of the behavior of the system. The physical properties of the observed data are further shown via MATLAB simulations. Sensitivity analysis computes parameters, revealing their impact on species behavior, visually presenting the parameter impact. [ABSTRACT FROM AUTHOR]

In metallurgical practice, the material is considered of adequate quality if it meets the customer's expectations. It is necessary to take representative samples and perform quality testing to avoid financial and intangible losses. Sample contamination and matrix and surface quality play a significant role in the accuracy of chemical analyses. The purpose of this paper is to point out the advantages of specific methods of taking samples, such as immersion and spoon sampling of molten metal, and, in the experimental part, to assess the impacts of factors affecting the quality of the sampling. The influence of time of final sampling on determining the true amount of magnesium during a single melt and the influence of duration of mixing of molten cast iron on the accuracy of chemical analysis of the control sample were investigated. It is important that the time between the modification and casting of the liquid cast iron from the casting ladle be as short as possible. This is because the magnesium burns out and thus the chemical analysis of the sample taken is not accurate. Another important factor is ensuring the melt before sampling is homogenized and has the minimum prescribed temperature (1420 °C). Increasing sample collection time will cause changes in its chemical composition. [ABSTRACT FROM AUTHOR]

Schisandra chinensis (S. chinensis) has a long history as a traditional Chinese medicine that is astringent, beneficial to vital energy, tonifies the kidney, tranquilizes the heart, etc. Significantly, Schisandrol A (SA) is extracted from S. chinensis and shows surprising and satisfactory biological activity, including anti-inflammatory, hepatoprotective, cardiovascular protection, and antitumor properties, among others. SA has a more pronounced protective effect on central damaged nerves among its numerous pharmacological effects, improving neurodegenerative diseases such as Alzheimer's and Parkinson's through the protection of damaged nerve cells and the enhancement of anti-oxidant capacity. Pharmacokinetic studies have shown that SA has a pharmacokinetic profile with a rapid absorption, wide distribution, maximal concentration in the liver, and primarily renal excretion. However, hepatic and intestinal first-pass metabolism can affect SA's bioavailability. In addition, the content of SA, as an index component of S. chinensis Pharmacopoeia, should not be less than 0.40%, and the content of SA in S. chinensis compound formula was determined with the help of high-performance liquid chromatography (HPLC), which is a stable and reliable method, and it can lay a foundation for the subsequent quality control. Therefore, this paper systematically reviews the preparation, pharmacological effects, pharmacokinetic properties, and content determination of SA with the goal of updating and deepening the understanding of SA, as well as providing a theoretical basis for the study of SA at a later stage. [ABSTRACT FROM AUTHOR]

Analytical Chemistry course is a core professional course for chemistry majors and other related majors. Achieving the objectives of this course is crucial for the cultivation of professional talent. Effective implementation of teaching reform and design plays a significant role in enhancing the achievement of curriculum objectives. This paper aims to deepen the curriculum reform based on current implementation issues, and establish a triadic-driven curriculum reform and design model. This model integrates a learning community involving both teachers and students, promotes a seamless online and offline integration, emphasizes curriculum-based ideological and political education, pursues excellence in curriculum elements of profoundness-innovation-challenging, and continuously integrates Outcome-Based Education (OBE) philosophy. Thus, a curriculum reform model known as "unified body, dual-line integration, and triadic drive" has been constructed. [ABSTRACT FROM AUTHOR]