Talanta Open最新文献

Almond oils extracted from roasted kernels at different roasting times at 150 °C were analyzed to quantify quality parameters such as acidity, peroxide value, K₂₃₂, K₂₇₀, antioxidant activity and the oxidative stability index. The roasting process induced oxidation of the chemical compounds in the oil, resulting in increased acidity, peroxide value, K₂₃₂ and K₂₇₀. The antioxidant activity exhibited a decreasing trend over time, while the oxidative stability showed only slight changes. Excitation-emission matrices (EEMs) were directly scanned on almond oil samples. The combination of the EEMs with parallel factor analysis (PARAFAC) provided qualitative information about the main fluorophores and their evolution with the roasting time. Quantitative information was obtained using unfolded partial least squares (U-PLS), demonstrating the effectiveness of the fluorescence technique in combination with multivariate analysis to quantify analytical parameters in almond oils. Prediction models were developed, and subjected to external validation. The coefficients of determination in the external validation were higher than 0.94 for all parameters except k270.

Eu-MOFs have sparked widespread interest as a dependable, convenient, time-saving, highly sensitive, and specialised platform for analytical applications due to their strong skeletons, extremely high surface area, changeable pore sizes, easy functionalization, and great stability. This review will provide remarkable insight into the synthesis, structure, and properties of Eu-MOFs. Here, we will also focus on Eu-MOF applications as chemosensors, biosensors, selective gas adsorption, and chromatographic stationary phases in order to meet the needs of the materials used for analysis. Hence, this study will offer a comprehensive overview of existing research on the analytical applications of Eu-MOFs. We expect that this study will provide complete knowledge for researchers to recreate the procedures and contribute to future discoveries in this prominent field.

Designer fuel fraud consists in the smuggling of modified diesel blends as engine lubricant oils and their illegal trade avoiding payment of the excise duty applied to energy products. The fraudulent mixture contains regular diesel fuel plus a heavier hydrocarbon fraction, originating from waste automotive lubricant or cheap, residual base oils.

Raman spectroscopy was tested as a rapid in-situ screening method to separate regular diesel fuel samples from those suspected to contain a heavier component, and thus demanding a more extensive characterization. The Raman fingerprint region from the screened sample is matched to purposely created spectral libraries of compliant and non-compliant diesel fuels using the instrumental search algorithm. Overall, 177 compliant fuel samples and 28 non-compliant samples (all designer fuels with a confirmed heavier fraction and/or anomalous distillation parameters) were measured. The designer fuels were all positively identified, with ∼18 % false positives.

Subsequently, the Raman data-set was studied by Principal Component Analysis (PCA) and then classified as either compliant or non-compliant using Linear Discriminant Analysis (LDA). PCA using up to three principal components for data visualization shows only an incipient separation but still a partial overlap between compliant and non-compliant samples. LDA, on the opposite, performed superiorly in the binary classification task, with no false negatives and less than 4 % false positives.

A novel and major cannabinoid (epicannabidiol hydrate) present in hemp plants and oils was isolated and characterized by a combination of flash chromatography and liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC/Q-TOF-MS). This novel cannabinoid differs from cannabidiol (CBD) by the absence of a double bond in the terpene ring and the presence of an additional hydroxyl group in the same terpene ring. The isolation procedure involved the use of normal phase chromatography with a silica gel preparative column, followed by reversed phase chromatography with a C18 preparative column. In this way, other major cannabinoids present in the samples, such as cannabidiol and Δ9-tetrahydrocannabinol, were separated and the focus was placed on the novel cannabinoid compound. Exact accurate masses were obtained for the compound of interest at m/z = 333.2424 in positive ion mode and m/z = 331.2279 in negative ion mode. Additional MS-MS analysis in negative ion mode revealed the position of the additional hydroxyl group in the molecule. Finally, the structural characterization was corroborated with ¹H NMR and ¹³C NMR analysis, thus verifying the exact chemical structure of this novel cannabinoid, which has not previously been reported in hemp samples.

Multiwall carbon nanotubes (MWCNTs) were modified through deferoxamine mesylate and used as an adsorbent for separation and preconcentration of the trace amount of iron ions in food samples followed by a simple, fast and sensitive spectrophotometric method was developed for the termination. The proposed separation and preconcentration method was performed in short time by using a small amount of chemical solvent. Also, the used adsorbent was environmentally friendly and highly compatible with the human body.

In this study iron was complex with deferoxamine. After extraction, the complex was eluted by HCl 2 % (v/v) and analyzed by a fast, straightforward, and inexpensive UV–Visible spectrometer method. The determination was performed with high selectivity, sensitivity and good accuracy. The calibration curve was linear in the range of 0.12 µg.L⁻¹ to 500 µg.L⁻¹. The detection limit was obtained 0.08 µg.L⁻¹. The suggested method was used for measuring the trace amount of iron ions in the five food samples: spinach, parsley, cooked pinto beans, and cooked sheep's liver. Based on the obtained results, the proposed method has shown proper sensitivity, accuracy, and repeatability.

Gold nanoparticles (AuNPs) have become the focus of rapid research due to their unique optical and electronic properties. There has been a noticeable increase in papers relating to AuNPs, with over 71,000 publications between 2019 and 2024. AuNPs possess exceptional stability, low resistance, high conductivity, and extensive light interaction, making them well-suited for biological sensing applications. This literature study begins by examining different approaches for synthesizing AuNPs, including chemical, physical, and biological methods, before exploring their use as biosensors. A comprehensive examination of the various detection methods, including localized surface plasmon resonance (LSPR), luminescence, surface-enhanced Raman scattering (SERS), surface plasmon resonance (SPR), and electrochemical properties, is facilitated through an exploration of the fundamental principles and classification of biosensors. We primarily focus on using AuNPs in medical diagnostics, highlighting current advancements in disease detection with AuNPs-based biosensors for conditions like COVID-19, dengue fever, and diabetes. The review emphasizes current research achievements in AuNPs synthesis and the bright prospects for their use in biocompatible and efficient biosensor applications.

Evaluation of anti-inflammatory drug on a two-way membrane-integrated microfluidic device (TMMD) is presented. Insertion of a porous membrane into a microfluidic device in a vertical direction and attachment of a cover glass to the lateral side of the microfluidic device enabled us to observe the device from two orthogonal directions. HaCaT, a human epidermal keratinocyte, was cultured in the TMMD. The localization of ZO-1, a tight junction protein, between the HaCaT cells was confirmed by immunohistochemical analysis. Permeability of the HaCaT cell layer increased after stimulation by potassium dichromate, whereas the pretreatment of the HaCaT by dexamethasone prior to the stimulation kept the permeability unchanged. Deoxynivalenol, an anti-inflammatory drug candidate, kept the permeability unchanged with lower concentrations compared to dexamethasone. We expect that the present TMMD is applicable to various anti-inflammatory drug candidates to evaluate their efficacy.

Recent legalization and decriminalization of marijuana at the state level has not only contributed to a rise in the recreational use of Cannabis sativa, also known simply as Cannabis, but also to an increase in the range of matrices into which cannabinoids derived from it are infused. Traditional methods for analyzing these products, which are typically chromatography-based, are often matrix-dependent and demand time-consuming and resource-intensive sample preparation protocols that are highly nuanced and not readily applicable to multiple matrix types. Furthermore, the differentiation of cannabinoids can be troublesome without implementing lengthy run times to achieve resolution of chromatographic peaks. With complex samples such as edibles, beverages, personal-care products, and plant materials, a method that can be more universally applied to rapidly detect and differentiate between cannabinoids is highly desirable. In this study, foods and personal-care products under the categories of sweets, spreads, condiments/toppings, beverages, oils, and commercial body products were spiked with cannabinoids including Δ⁹-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabicitran (CBT), and cannabigerol (CBG). Chemical derivatization of the samples with N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) followed by direct analysis in real time – high-resolution mass spectrometry (DART-HRMS) analysis readily revealed the presence of cannabinoids in the products despite the matrix complexity (i.e., the contributions from matrix-derived peaks did not interfere with the differentiation of cannabinoids). When analyzed under ambient soft ionization conditions, CBT, THC and CBD are indistinguishable because they are isomers with a molecular formula of C₂₁H₃₀O₂ and a protonated monoisotopic mass of 315.2324. However, due to the different number of hydroxyl (-OH) groups (zero in CBT, one in THC, and two in CBD) that engage with the derivatizing agent, the cannabinoids are differentiated based on the mass disparities of the protonated adducts formed (m/z 315.2324, 387.2719 and 459.3119 for CBT, THC, and CBD, respectively), which is readily revealed by DART-HRMS. This approach circumvents some of the challenges currently encountered by forensic laboratories in the analysis of highly complex and diverse cannabinoid-infused matrices. The results show proof-of-concept for an approach that can aid in the differentiation of cannabinoid isomers by DART-HRMS that accommodates high matrix diversity and complexity, and demonstrates the potential for the approach to be integrated into current workflows for the forensic analysis of Cannabis-related materials and evidence.

A series of experiments are described that provide recommendations of modifications to leaching test specifications to minimize losses of mercury from eluates during leaching tests and management of analytical samples. EPA methods of the Leaching Environmental Assessment Framework (LEAF) were used as a reference point for what steps are most likely to see losses, including filtration, storage of unpreserved mercury contaminated material, and materials of construction for vessels. The potential sorption of mercury to borosilicate glass and PTFE lab materials was tested to determine what materials are suitable to replace HDPE and polypropylene. The experimental findings indicate that bottles constructed of PTFE and Type I (borosilicate) glass are recommended as extraction and containment vessels for mercury-containing liquids. Type I syringe filtration of aqueous mercury samples at pH 2 through 9 through 0.45 µm PTFE filters housed in polypropylene is acceptable; however, sorption losses were observed to occur at pH > 9. Storage of unpreserved liquids containing mercury over extended leaching test intervals did not lead to significant losses of mercury when coupled with minimized headspace. All mercury-containing eluates should include preservation with Optima HNO₃ to a 1 % concentration and gold (III) standard to a concentration of 200 µg/L, followed by refrigeration at <6 °C prior to analysis.

Having economical, flexible, disposable and readily manufacturable devices for everyday sensing applications is of paramount importance. We report a novel and cost-effective technique for fabricating paper-based devices using an Advanced PAP (A-PAP) pen, which is capable of withstanding typical aqueous solutions and organic solvents. The quick fabrication process does not require any sophisticated instrumentation or a heating step, making it a promising technology for resource-limited settings. Using an A-PAP pen, we have fabricated two-dimensional (2D) paper-based devices for chemical detection of heavy metal and nitrite. We have also demonstrated the versatility of fabrication technique for biological sensing using 2D lateral flow paper-based devices for the detection of dopamine. Furthermore, the technique is also validated for fabricating complex three-dimensional (3D) paper-based devices using a paper origami technique for heavy metals sensing. The ready-to-use devices can be fabricated in seconds, making them convenient for on-the-spot testing. Overall, this technique provides a valuable tool for creating affordable, efficient, and accessible chemical and biological testing solutions.