Hasil untuk "Analytical chemistry"

Mehak Pant, Lubna Salman, Anupama V. Betigeri et al.

Background: Students belong to the most significant groups of individuals that use technology. Screen time impacts several factors including health and behavior. It is still mostly unknown how physical activity and screen-grounded programming interact to affect health-related quality of life. Methods: The study had been carried out as a crossed sectional survey. (google form survey circulated to participating university students). The student selection for this cross-sectional survey, included all undergraduate students aged 18–30 years, studying in MRIIRS, Faridabad. Participants-100, inclusion criteria age: 18–30 years university students exclusion criteria age: below 18 years. Results and Conclusion: The findings indicated that the combination of excessive screen time and no physical activity had the biggest detrimental effect on “health-related quality of life”.

Modar Sadek, Nazira Sarkis, George Jangi

This work presents the development and application of an innovative green supramolecular deep eutectic solvent (SUPRADES)-based DLLME approach for the extraction and quantification of melamine in milk matrices. For this purpose, thymol and nonanoic acid were combined to create a hydrophobic DES, which was then utilized as the extraction solvent. Additionally, a ternary SUPRADES based on a hydrophilic DES composed of choline chloride and ethylene glycol and doped with β-cyclodextrin (β-CD) was prepared and applied as the disperser solvent. Critical parameters were optimized systematically, yielding the following optimal conditions: Extraction solvent volume: 150 μL; disperser solvent: 600 μL; β-CD: 1% (w/v); pH: 7; extraction time: 1 min; and sample solution volume: 5 mL. Interestingly, the salting-out step did not affect the extraction efficiency. The optimized approach showed good linearity (100–900 ng/mL) with R2 = 0.998 when validated with matrix-matched calibration standards. The LOD and LOQ were 27 and 81 ng/mL, respectively, and the enrichment factor was 41. Method accuracy and precision were evaluated through recovery studies using milk samples fortified with melamine at three concentration levels (200, 500, and 800 ng/mL), and the recovery values were obtained in the range of 92–107%, with RSD < 5%. A greenness score of 79 was attained by the method, as quantified by the advanced ComplexMoGAPI. Lastly, this technique was successfully applied to extract and determine melamine in real samples of powdered milk, infant formula, and raw milk with acceptable and satisfactory results.

M. Gaillard, A. Faure, P. Hily-Blant et al.

The spatial distribution of the chemical reservoirs in protoplanetary disks is key to elucidate the composition of planets, especially habitable ones. However, the partitioning of the main elements among the refractory and volatile phases is still elusive. Key parameters such as the carbon-to-oxygen C/O elemental ratio and the ionization fraction remain poorly constrained, with the latter potentially orders of magnitude lower than in the interstellar medium. Moreover, the thermal structure of the gas is also poorly known, despite its deep influence on gas-phase chemistry. In this context, ortho-to-para ratios could provide selective and sensitive probes. Recent ALMA observations have measured the spatially resolved column density of ortho-and para-H2CO in the transition disk orbiting TW Hya and derived the radial profile of the ortho-to-para ratio. Yet, current disk models do not include the nuclear-spin-resolved chemistry required to interpret these observations. The present work aims to fill this gap, by combining a parametric disk physical model of TW Hya with the UGAN network, updated to include a comprehensive description of the nuclear-spin-resolved chemistry of formaldehyde. This new model reproduces the observed column density of H2CO to within a factor of 2, as well as the measured ortho-to-para ratio which varies from 1.5 in the outer disk to 3 inside 90au. In particular the low value of this ratio beyond 90au is well explained by our model. However, the statistical value of 3 measured below 70au cannot be reproduced, suggesting that additional processes involving ices may be involved. Our parameter space exploration shows that the abundance of H2CO is highly sensitive to the C/O elemental ratio and to the cosmic-ray ionization rate. Future observations of ortho-and para-H2CO, based on well selected rotational transitions, in a large sample of disks, appear highly desirable.

Neelam Gusain, Ashish P. Anjankar, Ranjit S. Ambad et al.

One of the biggest health issues facing women in their childbearing years worldwide is polycystic ovarian syndrome, or PCOS. PCOS is a prevalent endocrine condition with well-known negative effects on metabolism, reproduction, and cardiovascular health that contribute to substantial morbidity. There are still many unanswered questions regarding the precise mechanisms by which PCOS arises, and research into the disorder’s nature is ongoing. This study aims to investigate this uncharted horizon of PCOS by analyzing association between serum Caspase-1, IL-10, and biochemical indices relative to insulin resistance (HOMA-IR), hyperandrogenism (FAI), dyslipidemia, and oxidative stress in our female population. It expands on the significance of inflammation and insulin resistance, together with dyslipidemia in the advancement and signs and symptoms of PCOS. The work’s preface highlights the goal of advancing medical science’s ability to treat patients with illnesses and makes the case that interdisciplinary cooperation between gynecology, endocrinology, and biochemistry improves patient care. Our objective is to identify potential strategies to lessen the effects of PCOS in order to enhance the results of its diagnostic, therapeutic, and preventative measures for the millions of women who are affected.

Arın Gül Dal Poçan

Background: Fluconazole is a triazole antifungal agent widely employed in the treat ment of systemic and superficial fungal infections. Accurate, precise, and reliable quantification of the active pharmaceutical ingredient in dosage forms is of critical importance for both quality control and therapeutic efficacy. Methods: In this study, a reverse-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the quantitative determina tion of fluconazole in pharmaceutical preparations. Chromatographic separation was performed using a Zorbax C18 column (100 mm × 4.6 mm, 3.5 μm). The mobile phase consisted of a methanol–water mixture (70 : 30, v/v) in an isocratic system at a flow rate of 1.0 mL/min. The injection volume was set at 5 μL, the detection wavelength at 210 nm, and the column temperature at 30°C. The system suitability parameters of the method were found to be within the acceptable limits. Results: The retention time for fluconazole was determined as 1.13 ± 0.03 minutes. The method demonstrated linearity within the concentration range of 3.0 × 10−7 M to 9.0 × 10−6 M, with a correlation coefficient (r2) of 0.9999. The limit of detection (LOD) and limit of quantification (LOQ) were calculated as 6.0 × 10−8 M and 1.8 × 10−7 M, respectively. Accuracy and precision values were within acceptable ranges for both intra-day and inter-day analyses. Recovery values ranged from 96.2% to 101.3%, while the relative standard deviation values remained below 2%. Conclusion: The developed RP-HPLC method is a simple, accurate, precise, and robust approach that can be employed for the routine quality control of fluconazolen in pharmaceutical preparations. Moreover, the high sensitivity and reproducibility of the method indicate its potential applicability for the determination of fluconazole in biological samples in future studies.   Cite this article as: Dal Poçan AG. Development and validation of a rapid reverse-phase high-performance liquid chromatography method for quantification of fluconazole in pharmaceutical preparations. Trends in Pharmacy, 2025, 2, 0011, doi: 10.5152/TrendsPharm.2025.25011

Benedetta Paolino, Maria Cristina Sorrentino, Severina Pacifico et al.

In this study, a historically significant journal subject to fungal colonization was used as a case study for experimenting with a fumigation treatment using essential oils. The experiments were carried out both in vitro and in vivo directly on the artifact. Post-treatment monitoring showed that the succession of two fumigation treatments (alternately using rosemary and lavender oil) resulted in the complete disinfection of the first and second populations detected on the substrate. The latter was identified as <i>Trichoderma longibrachiatum</i>, a human pathogenic species, which was found to be sensitive to various concentrations of rosemary essential oil (1.2% <i>v</i>/<i>v</i>) and lavender essential oil (0.4% <i>v</i>/<i>v</i>), while it was not contained by the standard biocide based on benzalkonium chloride. The results obtained allowed the proposal of an application protocol for the fumigation of paper items that need to undergo biocidal treatment, which consists of alternating essential oils to increase the action spectrum of the natural substances and implementing a rotation principle to prevent the development of bio-resistances.

Yiming Cui, Xin Yao, Yuxuan Qin et al.

Multimodal scientific reasoning remains a significant challenge for large language models (LLMs), particularly in chemistry, where problem-solving relies on symbolic diagrams, molecular structures, and structured visual data. Here, we systematically evaluate 40 proprietary and open-source multimodal LLMs, including GPT-5, o3, Gemini-2.5-Pro, and Qwen2.5-VL, on a curated benchmark of Olympiad-style chemistry questions drawn from over two decades of U.S. National Chemistry Olympiad (USNCO) exams. These questions require integrated visual and textual reasoning across diverse modalities. We find that many models struggle with modality fusion, where in some cases, removing the image even improves accuracy, indicating misalignment in vision-language integration. Chain-of-Thought prompting consistently enhances both accuracy and visual grounding, as demonstrated through ablation studies and occlusion-based interpretability. Our results reveal critical limitations in the scientific reasoning abilities of current MLLMs, providing actionable strategies for developing more robust and interpretable multimodal systems in chemistry. This work provides a timely benchmark for measuring progress in domain-specific multimodal AI and underscores the need for further advances at the intersection of artificial intelligence and scientific reasoning.

Abdessamad Ettouil, Asmaa Oubihi, Hamada Imtara et al.

The extraction of gum from natural raw materials is of increasing importance in various industries, including food, pharmaceuticals, and cosmetics, particularly due to their emulsifying properties and potential applications as stabilizers and thickeners. This study presents an insight on the influence of changing parameters like reagents and operating condition on yield and some properties of the flax (Linum usitatissimum L.) seed gum. The extraction conditions were meticulously examined using a full factorial design, highlighting the significant impact of pretreatment, seed preparation, and solvent selection on the extraction yield. A response surface methodology (RSM) was then applied to optimize the water/benzoic acid ratio of the pretreatment step, the ethyl alcohol/water ratio, and the medium pH of the extraction method, resulting in a maximum yield of 14.47%. Furthermore, detailed analyses of the chemical and emulsifying properties of the gum were conducted showing emulsifying capacities over 94%, offering promising application prospects, particularly in the food industry.

Botao Yu, Frazier N. Baker, Ziru Chen et al.

To enhance large language models (LLMs) for chemistry problem solving, several LLM-based agents augmented with tools have been proposed, such as ChemCrow and Coscientist. However, their evaluations are narrow in scope, leaving a large gap in understanding the benefits of tools across diverse chemistry tasks. To bridge this gap, we develop ChemToolAgent, an enhanced chemistry agent over ChemCrow, and conduct a comprehensive evaluation of its performance on both specialized chemistry tasks and general chemistry questions. Surprisingly, ChemToolAgent does not consistently outperform its base LLMs without tools. Our error analysis with a chemistry expert suggests that: For specialized chemistry tasks, such as synthesis prediction, we should augment agents with specialized tools; however, for general chemistry questions like those in exams, agents' ability to reason correctly with chemistry knowledge matters more, and tool augmentation does not always help.

S Srinidhi, Sujithraj Stephen, Karthiga Mohankumar et al.

Although there is easy accessibility of infection control measures and recommendation regarding the PPE, most of the dentists failed to practice appropriate infection control measures. The aim of the current survey was conducted to assess the knowledge, perception, and attitude regarding the role of PPE among the dental care professionals in COVID-19. This is cross-sectional web-based questionnaire survey conducted among dental care professionals in Tamil Nadu. The self-administered questions related to the PPE infection control measures were collected from 500 subjects. The statistical analysis was done using Statistical Package for Social Sciences SPSS (V 22.0). The frequency distribution was computed. This survey revealed that all the 500 (100%) respondents had awareness about the role of PPE in COVID-19 pandemic. Among the 500 study subjects, 93.2% had well-known knowledge about PPE, 60.4% of dentist strictly adheres to the use of PPE in routine dental practice, 80.2% of dentist mentioned PPE is safe and effective against spread of infection, and 93.4% of dentist had awareness about donning and doffing. Conclusion: From the beginning of this COVID-19, information provided by the health organization like CDC and WHO regarding the role of PPE had positive impact among the dental care professionals.

Marjan Mirahmadi, Jesús Pérez-Ríos

Three-body recombination, or ternary association, is a termolecular reaction in which three particles collide, forming a bound state between two, whereas the third escapes freely. Three-body recombination reactions play a significant role in many systems relevant to physics and chemistry. In particular, they are relevant in cold and ultracold chemistry, quantum gases, astrochemistry, atmospheric physics, physical chemistry, and plasma physics. As a result, three-body recombination has been the subject of extensive work during the last 50 years, although primarily from an experimental perspective. Indeed, a general theory for three-body recombination remains elusive despite the available experimental information. Our group recently developed a direct approach based on classical trajectory calculations in hyperspherical coordinates for three-body recombination to amend this situation, leading to a first principle explanation of ion-atom-atom and atom-atom-atom three-body recombination processes. This review aims to summarize our findings on three-body recombination reactions and identify the remaining challenges in the field.

Tommaso Nottoli, Ivan Giannì, Antoine Levitt et al.

We present two open-source implementations of the Locally Optimal Block Preconditioned Conjugate Gradient (LOBPCG) algorithm to find a few eigenvalues and eigenvectors of large, possibly sparse matrices. We then test LOBPCG for various quantum chemistry problems, encompassing medium to large, dense to sparse, wellbehaved to ill-conditioned ones, where the standard method typically used is Davidson's diagonalization. Numerical tests show that, while Davidson's method remains the best choice for most applications in quantum chemistry, LOBPCG represents a competitive alternative, especially when memory is an issue, and can even outperform Davidson for ill-conditioned, non diagonally dominant problems.

Hammad Ullah, Yaseen Hussain, Cristina Santarcangelo et al.

Food spoilage makes foods undesirable and unacceptable for human use. The preservation of food is essential for human survival, and different techniques were initially used to limit the growth of spoiling microbes, e.g., drying, heating, salting, or fermentation. Water activity, temperature, redox potential, preservatives, and competitive microorganisms are the most important approaches used in the preservation of food products. Preservative agents are generally classified into antimicrobial, antioxidant, and anti-browning agents. On the other hand, artificial preservatives (sorbate, sulfite, or nitrite) may cause serious health hazards such as hypersensitivity, asthma, neurological damage, hyperactivity, and cancer. Thus, consumers prefer natural food preservatives to synthetic ones, as they are considered safer. Polyphenols have potential uses as biopreservatives in the food industry, because their antimicrobial and antioxidant activities can increase the storage life of food products. The antioxidant capacity of polyphenols is mainly due to the inhibition of free radical formation. Moreover, the antimicrobial activity of plants and herbs is mainly attributed to the presence of phenolic compounds. Thus, incorporation of botanical extracts rich in polyphenols in perishable foods can be considered since no pure polyphenolic compounds are authorized as food preservatives. However, individual polyphenols can be screened in this regard. In conclusion, this review highlights the use of phenolic compounds or botanical extracts rich in polyphenols as preservative agents with special reference to meat and dairy products.

Dong Lu

Abstract The purpose of the present research is to study the issues of inheritance and promotion of Chinese traditional music culture in college piano education. The research methodology builds on an empirical approach through a survey using a questionnaire for data collection. The present study involved 174 students from six Chinese colleges. Accordingly, students were divided into two groups based on the training approach. The experimental group included 87 students who received education under the previously elaborated program aimed at promoting Chinese traditional music culture; and the control group consisted of 87 students who received piano training under the conventional program. The results showed that for only 8% of the respondents the use of traditional Chinese music is the basis of learning, for 61% this type of music is practically not used. 88% of teachers concluded that there is a need to use Chinese traditional music in education because it displays elements that convey the symbolism of the Chinese people. The teaching criteria were to inform students about the need to apply Chinese national music while playing the piano; to introduce folk compositions for practicing technical elements into instruction; to update the repertoire and build students’ interest. Training based on the aforementioned criteria demonstrated that traditional music has become more popular. In particular, many students in the experimental group began to use this type of music while creating videos and shows (29%), participating in competitions and concerts (25%), and arranging musical compositions (21%). In the control group, students used folk music only while listening to musical compositions in their free time (57%) and teaching private piano lessons (11%). The present study has scientific and practical value as it demonstrates the effectiveness of promoting national music in educational institutions.

Renyuan Ma, Subash C. B. Gopinath, Thangavel Lakshmipriya et al.

Carcinoembryonic antigen (CEA) is a glycoprotein, one of the common tumor biomarkers, found at low levels in body fluids. Generally, overexpression of CEA is found in various cancers, including ovarian, breast, lung, colorectal, gastric, and pancreatic cancers. Since CEA is an important tumor biomarker, the quantification of CEA is helpful for diagnosing cancer, monitoring tumor progression, and the follow-up treatment. This research develops a highly sensitive sandwich aptasensor for CEA identification on an interdigitated electrode sensor. Carbon-based material was used to attach a higher anti-CEA capture aptamer onto the sensor surface through a chemical linker, and then, CEA was quantified by the aptamer. Furthermore, CEA-spiked serum was tested by using the immobilized aptamer, which was found to not affect the target validation. The limit of detection for CEA in PBS and serum is calculated from a linear regression graph to be 0.5 ng/mL with R2 values of 0.9593 and 0.9657, respectively, over a linear range from 0.5 to 500 ng/mL. This CEA quantification by the aptasensor can help diagnose various surgical tumors and monitor their progression.

Chao He, Joseph Serigano, Sarah M. Horst et al.

Chemistry in Titan's N2-CH4 atmosphere produces complex organic aerosols. The chemical processes and the resulting organic compounds are still far from understood, although extensive observations, laboratory, and theoretical simulations have greatly improved physical and chemical constraints on Titan's atmosphere. Here, we conduct a series of Titan atmosphere simulation experiments with N2-CH4 gas mixtures and investigate the effect of initial CH4 ratio, pressure, and flow rate on the production rates and composition of the gas and solid products at a Titan relevant temperature (100 K) for the first time. We find that the production rate of the gas and solid products increases with increasing CH4 ratio. The nitrogen-containing species have much higher yield than hydrocarbons in the gas products, and the N-to-C ratio of the solid products appears to be the highest compared to previous plasma simulations with the same CH4 ratio. The greater degree of nitrogen incorporation in the low temperature simulation experiments suggests temperature may play an important role in nitrogen incorporation in Titan's cold atmosphere. We also find that H2 is the dominant gas product and serves as an indicator of the production rate of new organic molecules in the experiment, and that CH2NH may greatly contribute to the incorporation of both carbon and nitrogen into the solid particles. The pressure and flow rate affect the amount of time of the gas mixture exposed to the energy source and therefore impact the N2-CH4 chemistry initiated by the plasma discharge, emphasizing the influence of the energy flux in Titan atmospheric chemistry.

Sarah Fruehwirth, Sandra Egger, Thomas Flecker et al.

Margarine contains a minimum of 80% fat and is therefore prone to lipid oxidation. While lipid oxidation in vegetable oils and <i>o</i>/<i>w</i> emulsions has been thoroughly investigated, studies about the oxidative stability and the identification of potential indicators of lipid oxidation in margarine are scarce. To evaluate the oxidative stability and to indicate the progress of lipid oxidation, four different types of industrial margarine (M1–M4), which differed in their composition of the minor ingredients and the oil phase, were stored at 15 °C for 180 days and analyzed at days 0, 1, 7, 14, 28, 56, 99, and 180 regarding peroxides, conjugated dienes, oxidized triacylglycerols, and volatiles. The peroxide value and the conjugated dienes increased up to 4.76 ± 0.92 meq O₂/kg oil and 14.7 ± 0.49 in M2, respectively. The oxidative stability decreased by a maximum of 50.9% in M4. We detected three different epoxidized triglycerides—TAG54:1 (O), TAG54:2 (O) and TAG54:3 (O)—in M3. Acetone could be identified, for the first time, as lipid oxidation product in stored margarine by headspace-solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). It increased in all types of margarine during storage by a maximum of 1070 ppb in M2. Acetone might be used as a new indicator for lipid oxidation in margarine.

Michael C. McCarthy, Brett A. McGuire

Astrochemistry lies at the nexus of astronomy, chemistry, and molecular physics. On the basis of precise laboratory data, a rich collection of more than 200 familiar and exotic molecules have been identified in the interstellar medium, the vast majority by their unique rotational fingerprint. Despite this large body of work, there is scant evidence in the radio band for the basic building blocks of chemistry on earth -- five and six-membered rings -- despite long standing and sustained efforts during the past 50 years. In contrast, a peculiar structural motif, highly unsaturated carbon in a chain-like arrangement, is instead quite common in space. The recent astronomical detection of cyanobenzene, the simplest aromatic nitrile, in the dark molecular cloud TMC-1, and soon afterwards in additional pre-stellar, and possibly protostellar sources, establishes that aromatic chemistry is likely widespread in the earliest stages of star formation. The subsequent discovery of cyanocyclopentadienes and even cyanonapthlenes in TMC-1 provides further evidence that organic molecules of considerable complexity are readily synthesized in regions with high visual extinction but where the low temperature and pressure are remarkably low. This review focuses on laboratory efforts now underway to understand the rich transition region between linear and planar carbon structures using microwave spectroscopy. We present key features, advantages, and disadvantages of current detection methods, a discussion of the types of molecules found in space and in the laboratory, and approaches under development to identify entirely new species in complex mixtures. Studies focusing on the cyanation of hydrocarbons and the formation of benzene from acyclic precursors are highlighted, as is the role that isotopic studies might play in elucidating the chemical pathways to ring formation.

Yu Liu, Kang-Kuen Ni

Advances in atomic, molecular, and optical (AMO) physics techniques allowed the cooling of simple molecules down to the ultracold regime ($\lesssim$ 1 mK), and opened the opportunities to study chemical reactions with unprecedented levels of control. This review covers recent developments in studying bimolecular chemistry at ultralow temperatures. We begin with a brief overview of methods for producing, manipulating, and detecting ultracold molecules. We then survey experimental works that exploit the controllability of ultracold molecules to probe and modify their long-range interactions. Further combining the use of physical chemistry techniques, such as mass spectrometry and ion imaging, significantly improved the detection of ultracold reactions and enabled explorations of their dynamics in the short-range. We discuss a series of studies on the reaction KRb + KRb $\rightarrow$ K$_2$ + Rb$_2$ initiated below 1 $μ$K, including the direct observation of a long-lived complex, the demonstration of product rotational state control via conserved nuclear spins, and a test of the statistical model using the complete quantum state distribution of the products.

Alexey Potapov, Martin McCoustra

Dust grains play a central role in the physics and chemistry of cosmic environments. They influence the optical and thermal properties of the medium due to their interaction with stellar radiation; provide surfaces for the chemical reactions that are responsible for the synthesis of a significant fraction of key astronomical molecules; and they are building blocks of pebbles, comets, asteroids, planetesimals, and planets. In this paper, we review experimental studies of physical and chemical processes, such as adsorption, desorption, diffusion, and reactions forming molecules, on the surface of reliable cosmic dust grain analogues as related to processes in diffuse, translucent, and dense interstellar clouds, protostellar envelopes, planet-forming disks, and planetary atmospheres. The information that such experiments reveal should be flexible enough to be used in many different environments. In addition, we provide a forward look discussing new ideas, experimental approaches, and research directions.