Analytica

Boron nitride nanostructures (BNNs), including nanotubes, nanosheets, and nanoribbons, are renowned for their exceptional thermal stability, chemical inertness, mechanical strength, and high surface area, making them suitable for advanced material applications. Metal–organic frameworks (MOFs), characterized by their porous crystalline structures, high surface area, and tunable porosity, have emerged as excellent candidates for gas adsorption and storage applications, particularly in the context of hydrogen. This paper explores the synthesis and properties of BNNs and MOFs, alongside the innovative approach of integrating BNNs within MOFs to create composite materials with synergistic properties. The integration of BNNs into MOFs enhances the overall thermal and chemical stability of the composite while improving hydrogen sensing and storage performance. Various synthesis methods for both BNNs and MOFs are discussed, including chemical vapor deposition, solvothermal synthesis, and in situ growth, with a focus on their scalability and reproducibility. Furthermore, the mechanisms underlying hydrogen sensing and storage are examined, including physisorption, chemisorption, charge transfer, and work function modulation. Electrochemical characterization techniques, such as cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge–discharge, are used to analyze the performance of BNN-MOF systems in hydrogen storage and sensing applications. These methods offer insights into the material’s electrochemical behavior and its potential to store hydrogen efficiently. Potential industrial applications of BNN-MOF composites are highlighted, particularly in fuel cells, hydrogen-powered vehicles, safety monitoring in hydrogen production and distribution networks, and energy storage devices. The integration of these materials can contribute significantly to the development of more efficient hydrogen energy systems. Finally, this study outlines key recommendations for future research, which include optimizing synthesis techniques, improving the hydrogen interaction mechanisms, enhancing the stability and durability of BNN-MOF composites, and performing comprehensive economic and environmental assessments. BNN-MOF composites represent a promising direction in the advancement of hydrogen sensing and storage technologies, offering significant potential to support the transition toward sustainable energy systems and hydrogen-based economies. Full article

This study describes the development of an optical-based surface plasmon resonance (SPR) aptasensor for the detection of cocaine. The aptasensor was prepared by first attaching gold nanoparticles to a clean SPR chip surface, followed by the addition of an aptamer to create a modified surface. This surface was characterized using contact angle and atomic force microscopy, revealing surface roughness values of 0.28 nm and 28.12 nm for the blank and modified surfaces, respectively. The detection of cocaine was carried out in the concentration range of 1 ng/mL to 1000 ng/mL, with a detection time of approximately 8 min and a cocaine limit of detection (LOD) of 0.43 ng/mL. Repeatability studies were conducted, and the stability of the signal response was examined at a concentration of 200 ng/mL. Adsorption isotherm models, including Scatchard, Langmuir, and Freundlich models, were calculated to assess the surface homogeneity of the SPR aptasensor chip, with the results indicating compatibility with the Langmuir isotherm model. Full article

Complexation between carnitine and acetylated or benzylated pyrogallol[4]arenes was studied in DMSO via dynamic NMR, UV-vis spectroscopy, and in the gas phase via electrospray ionization-mass spectrometry (ESI-MS). In the presence of benzylated tetra(phenyl)pyrogallol[4]arene, the interaction with carnitine via NMR was evident and was confirmed by means of UV-vis spectroscopy, where the formation of a host–guest-type complex was observed; this was stable and exhibited a change to a clear color. With benzylated tetra(propyl)pyrogallol[4]arene, the results showed that there was no interaction with the neurotransmitter. A plausible explanation for this behavior is based on the dynamic behavior of the benzylated tetra(propyl)pyrogallol[4]arene, and this shows the dependence on the size of the cavities and the substituent on the lower rim of the pyrogallo[4]arenes. Suitable crystals of O-acetylated-tetra(propyl)calix[4]pyrogallolarene were obtained and were characterized through an X-ray crystal structure determination. Full article

Three-dimensional printing technology has emerged as a versatile and cost-effective alternative for the fabrication of electrochemical sensors. To enhance sensor sensitivity and biocompatibility, a diverse range of biocompatible and conductive materials can be employed in these devices. This allows these sensors to be modified to detect a wide range of analytes in various fields. 3D-printed electrochemical sensors have the potential to play a pivotal role in personalized medicine by enabling the real-time monitoring of metabolite and biomarker levels. These data can be used to personalize treatment strategies and optimize patient outcomes. The portability and low-cost nature of 3D-printed electrochemical sensors make them suitable for point-of-care (POC) diagnostics. These tests enable rapid and decentralized analyses, aiding in diagnosis and treatment decisions in resource-limited settings. Among the techniques widely reported in the literature for 3D printing, the fused deposition modeling (FDM) technique is the most commonly used for the development of electrochemical devices due to the easy accessibility of equipment and materials. Focusing on the FDM technique, this review explores the critical factors influencing the fabrication of electrochemical sensors and discusses potential applications in clinical analysis, while acknowledging the challenges that need to be overcome for its effective adoption. Full article

The GPHF-Minilab™ is a portable toolkit for performing qualitative methods such as thin-layer chromatography (TLC) on common pharmaceuticals. It is particularly useful in resource-limited locations where it is more challenging to monitor for substandard and falsified (SF) medicines. However, the GPHF-Minilab™ TLC methods are only semi-quantitative at best and thus have issues monitoring product quality effectively. We have improved on the GPHF-Minilab™ TLC method for metronidazole, a common antibiotic, by making it fully quantitative. Sample solutions were spotted on TLC plates alongside three metronidazole standards at different concentrations. After development, plates were imaged in a lightbox with two different smartphone cameras. Images were processed through the open-source program ImageJ and resulting pixel data from the standard spots were used to create a calibration curve, enabling quantitation of the sample. The USP Metronidazole Tablet high-performance liquid chromatography (HPLC) assay was used as the reference method. We validated this TLC method using 250 and 500 mg metronidazole tablets from different manufacturers and assessed linearity, range, accuracy, precision, intermediate precision, specificity, and robustness. These improvements should enhance the GPHF-Minilab™ TLC methods for metronidazole product screening. Additionally, the procedure is extensible to other analytes, although further validation would be required for each Minilab method. Full article

This study examines the significant impact of bacterial, algal, and fungal toxins on foodborne illnesses, and stresses the importance of advanced detection techniques, such as high-performance liquid chromatography (HPLC)-based methodologies. It emphasizes the urgent need for further advancements in these techniques to ensure food safety, as they offer significant benefits, including low detection limits and the ability to be combined with other techniques to detect a wide range of toxins. In this regard, HPLC has emerged as a versatile and sensitive analytical technique for this purpose. Various HPLC methods, often enhanced with detectors such as ultraviolet (UV), fluorescence (FD), and mass spectrometry (MS), have been developed to identify and quantify microbial toxins in a wide variety of food samples. Recent advancements include HPLC-FD methods that utilize the natural fluorescence of certain aflatoxins, improving detection sensitivity. HPLC-MS/MS and UHPLC-MS/MS techniques offer high selectivity and sensitivity, making them suitable for detecting a wide range of toxins in trace quantities. The adaptability of HPLC, combined with innovative detection technologies and sample preparation methods, holds significant potential for enhancing food safety monitoring and reducing the global burden of foodborne diseases. Full article

Multidrug-resistant bacteria have complicated the treatment of gastrointestinal diseases; their microbial resistance stems from the indiscriminate use of medications and the transfer of resistance genes. Varronia curassavica Jacq., a plant traditionally used to treat rheumatic and gastrointestinal diseases in underserved populations, has sparked interest as a potential source of antimicrobial compounds. This study aimed to investigate the chemical composition and antibacterial effects of V. curassavica essential oil and to evaluate its toxicity in Drosophila melanogaster. The essential oil was extracted through hydrodistillation and its chemical composition was determined using GC-MS. Antibacterial tests were performed with microdilution. The results showed the presence of major compounds including α-pinene and β-caryophyllene. The essential oil did not show relevant MIC, but it enhanced the effects of the antibiotics, gentamicin, norfloxacin, and oxacillin. It exhibited no toxicity and did not affect geotaxis, even at high concentrations. The in silico analysis of α-pinene revealed low toxicity; however, its permeability to the BBB shows that caution is needed in its application. These results indicate that the essential oil of V. curassavica shows promising potential in enhancing pharmaceuticals to prevent increased bacterial resistance. In addition, it demonstrated safe aspects when tested on D. melanogaster. Full article

Optimizing forage quality is vital for enhancing animal performance and supporting the global animal production industry. Near-infrared (NIR) spectroscopy offers a rapid, non-destructive alternative to traditional, time-intensive laboratory analyses, enabling the on-site assessment of forage properties with significant advantages in cost, speed, and environmental impact. This review traces the development of NIR spectroscopy, outlines its core principles, and highlights its applications in animal nutrition. Additionally, it discusses the current technological state, challenges, and future prospects, emphasizing NIR’s growing role in promoting more sustainable and efficient animal production systems. Full article

A pressurized liquid extraction (PLE) method for the extraction of 31 organophosphate esters (OPEs) and novel organophosphate esters (NOPEs) has been developed. Unlike previously published methods, this method utilizes the high-throughput nature of PLE (as opposed to Soxhlet or sonication methods) without using potentially harmful organic solvents like methylene chloride. Combinations of hexane and acetone and hexane and ethyl acetate at various temperatures were examined. Extracts were concentrated and analyzed via gas chromatography–mass spectrometry. The final optimized method utilized 1:1 v/v hexane/ethyl acetate at 100 °C for three static cycles (5 min each) at 80% flush volume and a 100 s N₂ purge. This provided average surrogate corrected target analyte percent recoveries in spike and recovery experiments (n = 6) for OPEs and NOPEs of 106 ± 13%, with average surrogate recoveries of 88.6 ± 7.3%. The developed method was further validated using standard reference materials and was then applied to atmospheric particulate matter samples collected in the city of Providence, RI. The dataset reflected ambient concentrations of 16 OPEs and NOPEs (reported in pg m⁻³) for the first time in the greater Providence metropolitan area, including one of the first reports of NOPEs in atmospheric particulate matter in the U.S. Full article

Nuclear magnetic resonance (NMR) is a technique used for many years by chemists for elucidation of molecular structure. Technological progress over the years has enabled this technique, making it easier to use. Thus, the LF-NMR (low-field NMR) was introduced as a side technique, characterized by low management costs and shorter analysis time than its main counterpart. The application of ¹H LF-NMR for the quantification of ethyl alcohol in different alcoholic matrices is herein described, comparing the results obtained with this technique with those determined by a reference gas chromatographic method. Full article

Abstract: The green analytical procedure index (GAPI) has been widely used to assess the greenness of different steps in analytical methodology. In the GAPI index, the different stages of the chemical analysis process are depicted using five pentagrams divided in subsections, labeled green, yellow, or red according to the degree of greenness. This GAPI tool provides a quick overview of the environmental impact and safety of the procedure. However, there is no total score that can be calculated from the GAPI metric to enable comparison between methods. In this work, a modified GAPI tool (MoGAPI) and software have been developed and applied to address the limitations of the current GAPI metric. The presented tool offers a more precise assessment of greenness, while the software simplifies and expedites its application. It also combines the advantages of the analytical Eco-Scale with the merits of the widely used GAPI metric. This tool was successfully applied to calculate the greenness of a few case studies and applications to show the applicability of this modified metric. The software for the MoGAPI tool is also freely available (open source) at bit.ly/MoGAPI to facilitate application and method comparison. The MoGAPI tool and its software represent a significant advancement in greenness assessment, providing researchers with a robust and user-friendly means to evaluate and compare analytical methods. Full article

Varronia curassavica Jacq. is an aromatic species appertaining to the Boraginaceae family and has been mentioned for its numerous traditional uses and pharmacological properties, especially its antimicrobial and anti-inflammatory effects. The aim of the present study was to investigate the phytochemical profile and antifungal activities of the essential oils of V. curassavica, in addition to analyzing the ADMET properties of the majority components. The GC-MS analysis of V. curassavica essential oil (EOVC) comprised 97.36% of total composition, with α-pinene, β-caryophyllene, and bicyclogermacrene (44.46%, 22.87%, and 13.05%, respectively) as the main constituents among other minor/trace constituents. The antifungal activity of EOVC was evaluated against three Candida species and was observed with IC₅₀ > 200 μg/mL. Remarkably, the combination of EOVC with fluconazole significantly reduced the IC₅₀ required for the drug to inhibit C. tropicalis (0.003 μg/mL), C. albicans (0.7996 μg/mL), and C. krusei (17.73 μg/mL). In addition, ADME/Tox studies using α-pinene revealed that the compound poses no toxicity threats but requires caution due to its high permeability to the blood–brain barrier (BBB). Overall, the obtained results suggest that Varronia curassavica essential oil is a potentially good antifungal agent for combating fungal resistance. Full article

A method to determine aceclofenac, ketorolac, and sulindac in human urine samples using microemulsion electrokinetic chromatography (MEEKC) has been developed in this study. The optimization of MEEKC conditions was carried out by changing the microemulsion compositions including the buffer pH, borate salt concentration, surfactant concentration, co-surfactant concentration, organic modifier concentration, and oil droplet concentration. The optimum separation of selected drugs was obtained with a composition of microemulsion containing 10 mM borate buffer pH 9, 0.5% sodium dodecyl sulphate (SDS), 6.6% n-butanol, 6.0% acetonitrile, and 0.8% ethyl acetate. Excellent linearity was obtained in the range concentration of 25 to 200 ppm with r² > 0.999. Limits of detection (LOD, S/N = 3) and limits of quantification (LOQ, S/N = 10) were 2.72 to 4.75 and 9.08 to 15.85 ppm, respectively. The solid-phase extraction (SPE) method using C-18 as an adsorbent and the solid phase micro-tip extraction (SPMTE) method using multiwalled carbon nanotubes (MWCNTs) as an adsorbent were used to clean-up and pre-concentrate the urine samples prior to the MEEKC analysis. The best recoveries of the selected drugs in the spiked urine sample were 91 to 103% with RSD of 1.26 to 4.03% (n = 3) using the SPE-MEEKC method. Full article

The main aim of this study was to determine the effects of different processing methods on the antinutritional factors of mungbean (Vigna radiata L.) of the Pusa Baisakhi variety. The values obtained were as follows: tannin 477 mg/100 g, oxalate 227 mg/100 g, phytate 627 mg/100 g, total phenolic content 772 mg/100 g, and saponin 2618 mg/100 g in raw mungbean, on a dry basis. The maximum reduction in tannin (63%) was observed when the mungbean was processed by the soaking and dehulling processes. The reduction achieved by soaking for 12 h and germination for 36 h was the most effective method in reducing the phytate content of mungbean (39%). The maximum reduction in saponin (22%) and oxalate (71%) was observed by autoclaving the soaked seeds. In comparison to other methods, roasting was the least effective method to reduce tannin, phytate, and oxalate. Autoclaving of the soaked seeds was the most effective method for reducing the antinutrients of mungbean among the cooking treatments. The processing methods such as soaking, dehulling, germination, roasting, raw open cooking, raw autoclaving, soaked open cooking, and autoclaving of soaked seeds significantly reduced the antinutrient contents of mungbean (p < 0.05). However, the effects of the treatments combined were more effective than those of the single process. Full article

Canine olfaction is a highly developed sense and is utilized for the benefit of detection applications, ranging from medical diagnostics to homeland security and defense prevention strategies. Instrumental validation of odor delivery methods is key to standardize canine olfaction research to establish baseline data for explosive detection applications. Solid-phase microextraction gas chromatography (SPME/GC-MS) was used to validate the odor delivery of an olfactometer. Three explosive classes were used in this study: composition C-4 (C-4), trinitrotoluene (TNT), and ammonium nitrate (AN). Dynamic airflow sampling yielded the successful detection of previously reported target volatile organic compounds (VOCs): 2,3-dimethyl-2,3-dinitrobutane (DMNB) in C-4 and 2-ethylhexan-1-ol (2E1H) in ammonium nitrate and TNT across odor dilutions of 80%, 50%, 25%, 12%, and 3%. C-4 highlighted the most reliable detection from the olfactometer device, depicting a response decrease as a function of dilution factor of its key odor volatile DMNB across the entire range tested. TNT only portrayed 2-ethylhexan-1-ol as a detected odor volatile with a detection response as a function of dilution from 80% down to 12%. Comparatively, ammonium nitrate also depicted 2-ethylhexan-1-ol as an odor volatile in the dynamic airflow sampling but with detection only within the upper scale of the dilution range (80% and 50%). The results suggest the importance of monitoring odor delivery across different dilution ranges to provide quality control for explosive odor detection using dynamic airflow systems. Full article

The current research investigation aimed to screen the bioactive compounds in the latex of Calotropis gigantea L. and evaluate its antibacterial and antioxidant properties towards clinical applications. The chemical moiety and volatile compounds of the latex of C. gigantea were detected by UV–Vis spectroscopy, FT-IR, and GC–MS analysis. The antibacterial activity was assessed using wound-inducing pathogens by well diffusion method. In addition, the antioxidant properties were determined through DPPH, ABTS, and FRAP methods. The functional groups of O–H stretch, diketonic bonds, C–O, C–N, O–C bonds, and consecutive C–H bonds were observed in the latex of C. gigantea. The major bioactive compounds were 5H-3,5a-Epoxynaphth[2,1-c]oxepin, Cholesta-5-en-3-ol, 24-propylidene-, dodecane, Lup-20(29)-Ene-3,28-Diol, (3.Beta)-, Veridiflorol, and Lanosta-8,24-dien-3-ol, acetatate, (3.beta.). Oxazole derivatives were found in the latex of C. gigantea, proved by GC–MS analysis. The aqueous-mixed latex exhibited maximum antioxidant activity as compared to methanol-mixed latex. Aqueous-mixed latex and methanol-mixed latex inhibited the growth of K. pneumoniae, P. mirabilis, S. pyogenes, Micrococcus spp., S. aureus, P. aeruginosa, and E. coli. The present study clearly reveals that latex of C. gigantea has rich bioactive compounds with significant biological activities, and can be employed to produce a novel herbal formulation against wound-inducing pathogens. Full article

Heavy metals represent a class of chemical elements that includes metalloids, bases and transition metals, lanthanides, and actinides. They are distinguished for their toxicity in small concentrations and their negative effects on the environment and human health; consequently, their monitoring has to be improved to manage the risks. The determination of heavy metals is carried out mainly by analytical methods, using spectroscopy, spectrometry, and electroanalysis. However, the interest has shifted to new and faster methodologies and techniques for heavy metal analysis, with particular emphasis on voltammetry. Voltammetry is preferred for heavy metal detection owing to the advantages of low cost, simplicity, ease of operation, fast analysis, portability, the ability to monitor environmental samples in the field, and high sensitivity and selectivity. Therefore, this study summarizes the applications of voltammetry in heavy metal determination mainly in water, soil, and plant samples, and presents an evaluation of sensitivity, selectivity, and applicability. Full article

This work describes a two-stage technique of X-ray fluorescence (XRF) analysis of rare earth niobates. A comparison between the two approaches revealed that the Fundamental Parameters Method (FPM) can be employed for a rapid preliminary assessment of the composition of the resulting material and the construction of calibration curves can be used to determine the contents of the major elements with precision. The results of the relative standard deviation (RSD) for FPM were no more than 7%, while the approach to construct calibration curves had an RSD of no more than 1%. Calibration samples were prepared using the same synthesis method as the study samples to construct the calibration curves. The possibility of constructing calibration dependencies using mixtures of oxides was assessed, but this approach could not provide the desired accuracy. The obtained results have been shown to have a good correlation with inductively coupled plasma optical emission spectrometry. The developed technique enables the determination of the major components in niobates containing two and three rare earth elements, which are used as optical materials and medium-entropy ceramics. Full article