Talanta Open最新文献

Chloride (Cl⁻) is an anion widely distributed in nature. It is also an essential parameter to consider when assessing the water quality for ensuring drinking water safety, preventing infrastructure damage, mitigating environmental impact, identifying groundwater contamination. This work presents the first development of a diameter-based measurement paper sensor for chloride analysis using the reaction based on a Mohr's precipitation titration. The paper sensor that has a circular shape with 3-cm diameter was pre-coated with AgNO₃ and CrO₄²⁻ forming brown precipitates of the Ag₂CrO₄. The sensor was sealed using lamination films with 3-mm diameter hole-punched inlets on the top of the lamination film for sample delivery. To detect chloride, the sensor was simply immersed into the sample. The chloride solution flows into the central sample inlet and spreads radially to undergo the displacement reaction with Ag₂CrO₄ precipitate, forming AgCl white precipitate whose diameter proportional to the chloride that can be observed within 3 min. Concentration of AgNO₃ used was found to impact the analytical figures of merit. The lower AgNO₃ concentration yields lower limit of detection, narrower linear range but higher sensitivity. The sensor was applied for chloride analysis in tap water, drinking water and industrial water and the chloride concentration obtained from the developed sensors are not significant differences from those obtained from the standard titration method at 95% confidence interval (two tailed P = 0.08) indicating that the developed sensor provides accurate analysis of chloride in water samples from various sources. The developed sensor was used by the untrained staffs for on-site of analysis chloride in tap water collected at 26 locations in SaenSuk Municipality area, Chonburi, Thailand. The results showed that the chloride level in all samples is in range of 52.2–84.7 mg L⁻¹ which is far below the acceptable range set by the Provincial Waterwork Authority of Thailand (< 250 mg L⁻¹) indicating that the tap water used in this area is safe for consumers.

The entry of pharmaceuticals into water is a key worldwide concern, with drugs being identified in all near-aqueous ecologies at often worrying concentrations. Pharmaceutical waste in environmental water has been shown to affect environmental equilibrium and pose a risk to humans adversely. In the present study, we fabricated a novel system containing 3D printed sustainable, porous Polyethylene terephthalate glycol (PETG) cartridges and RP-HPLC-DAD methodology to remove non-steroidal anti-inflammatory drugs (NSAIDs) such as diclofenac sodium (DS) and indomethacin (IND) from water samples called “Cartridges.” The device was fabricated using fused deposition modeling (FDM)-mediated 3D printing technology using indigenous hot-melt extruded filaments. To enable FDM 3D printing, the filaments were fabricated using PETG as a primary material and polyvinyl alcohol (PVA), Affnisol™, and Eudragit®EPO as water-soluble pore-forming materials. We showed that the thermoplastic, recyclable PETG composite material, which presents microporous properties after removal of PVA, Affnisol™, and Eudragit®EPO, is effective for extracting both drugs from water solution. The usefulness of the current strategy was demonstrated by the extraction of DS and IND from an aqueous solution followed by RP-HPLC analysis. The% extraction recovery was more than 80 % for both drugs, with an overall relative standard deviation of less than 3 %. The proposed approach can bring a ray of hope in extraction and sample preparation in the analytical industry due to a shift to the use of sustainable cartridges with customizable shapes, sizes, and chemical properties.

Nitrogen dioxide (NO₂), a common air pollutant, has been widely admitted to be harmful to both the environment and human health, demanding its well-control procedure and corresponding quantification. In this study, NO₂ in ambient air was collected by a passive sampling method using the Willems badge diffusive sampler, followed by a derivatization step with the Griess-Saltzman solution, and analyzed by ultraviolet-visible (UV–vis) spectroscopy at 543 nm. The device can be utilized for 168 h of continuous field sampling. The experimental sampling rate (K_e) of (4.02 ± 0.29) × 10⁻³ m³ h ^{− 1} with a relative standard deviation (% RSD) of 9.6 % was determined by conducting parallel experiments between an active sampling method (ISO 6768:1998) and the Willems samplers. After exposure time, samplers could be stored for two weeks in a refrigerator at 4 °C before analyzing. The studied passive diffusive sampler was simple, low-cost, easy to reuse; permitted determining the average concentration of NO₂ in ambient air. The average NO₂ concentrations for 2-hour to 4-hour sampling periods at different studied sampling sites in Ho Chi Minh city (Vietnam) were ranged from 11.5 to 189 μg m ^{− 3}.

Rivaroxaban and aspirin are commonly used antithrombotic agents in combination to prevent coronary artery disease (CAD) and atherothrombotic events in adult patients after acute coronary syndrome (ACS) with elevated cardiac biomarkers, or with coronary artery disease (CAD) or symptomatic peripheral artery disease (PAD) in high-risk patients. The recommended dosage is 2.5 mg rivaroxaban twice daily in combination with 75–100 mg aspirin once daily. This study aimed to develop a fixed-dose combination tablet of rivaroxaban (2.5 mg) and aspirin (50 mg) to enhance medication adherence and decrease pill burden.

Compatibility studies were conducted on the active ingredients to develop the product formula. The formula and the manufacturing procedure were chosen based on the risk assessment for each active substance, wet granulation with both actives intragranular was found to have faster dissolution than direct mix formulae. Furthermore, a validated reverse-phase HPLC stability indicator method was developed to detect APIs and their possible degradants.

Despite growing decriminalization of Cannabis sativa (i.e., marijuana) possession throughout the United States of America, there remains to be an ongoing interest in the detection of unlawfully possessed and transported marijuana. This issue has resulted in an increasing interest regarding the generalization and specification related to the canine detection of marijuana. More specifically, canine trainers have expressed concerns on whether canines can generalize on the odor of marijuana regardless of the origin of their training materials. This research aims to differentiate multiple marijuana headspace samples from three regions in the USA based solely on the volatile organic compounds (VOCs) found in their odor profiles. In this study, a heated headspace solid phase micro-extraction (SPME) technique was optimized and implemented for the collection of both volatile terpenes and cannabinoids from marijuana. The headspace samples were analyzed using two full-scan, untargeted, optimized methods on a gas chromatograph coupled to a mass spectrometer (GC–MS), and a variety of chemometric tools were applied to the data to enable differentiation and potential classification between sample populations. Principal component analysis and sparse partial least squares discriminant analysis (sPLS-DA) employed in this study have demonstrated a disparity between marijuana varieties based on geography using the VOCs extracted from their odor profiles. With this research, it is intended to determine some fundamental differences between Cannabis of different geographical origins and set a foundation for the development and advancement of instrumental applications for other non-contact marijuana detection techniques in support of the improvement of illicit substance detection technology.

With the development of various radiation-based cancer therapies, radiobiological evaluation methods instead of traditional clonogenic assays with monolayer single cell culture are required to bridge gaps in clinical data. Heterogeneity within cancer tissues is the reason for bridging the gap between basic and clinical research in cancer radiotherapy. To solve this problem, we investigated an evaluation assay using a three-dimensional (3D) model of cancer tissue. In this study, a 3D model consisting of tumor and stromal layers was used to compare and verify radiobiological effects with conventional two-dimensional (2D) methods. A significant difference in the response to radiation was observed between the 2D and 3D models. The relative number of cancer cells decreased with X-ray dose escalations in the 2D and 3D models. In contrast, the relative number of normal cells was quite different between the 2D and 3D models. Considering the ability of cells to recover from radiation-induced damage, the histological results of the 3D model were reflected in the clinical data. Histopathological analysis using a 3D model is a potential method for evaluating radiobiological effects on the tumor and tumor margins.

Medicine counterfeiting is a worldwide problem affecting all therapeutic areas. The analysis of such products is sometimes a scientific challenge, since their chemical composition is unknown and might be very different from the one of the original product. While some counterfeited drug products are quite easy to detect, others are close in composition with the genuine products. The health consequences of counterfeit medicines are appalling since these products can contain the =rong chemical composition, impurities or toxic compounds, and be manufactured and stored in dreadful conditions that do not even respect the basic hygienic conditions. Providing reliable analytical tools is therefore necessary for an efficient fight against the phenomenon. In this study, the analysis of counterfeits of psychotropic drugs presenting a rare closeness in composition to the genuine drugs will be described. It will be exposed how the choice of reliable analytical strategy and tools is decisive for the correct authentication of such pharmaceuticals. The results of classical methods like High-Performance Liquid Chromatography (HPLC) will be presented. Then the contribution of vibrational spectroscopy and imaging tools, including spectral imaging and Near infrared (NIR) spectroscopy, and spectral imaging, will be described, as well as Gas Chromatography coupled with Mass Spectrometry (GC–MS), 1H Nuclear Magnetic Resonance (NMR), 3D microscopy as support for the physical analysis, and finally X-ray fluorescence spectroscopy (XRF) as an elemental analysis technology. The results of the forensic analysis will also reveal analytical links between the counterfeit cases, providing useful information for law enforcement investigations.

In this study, an equation for fitting the band lengths in µPADs to the concentrations/amount of analyte added to the µPAD sample area is derived. A simulation of the band formation is carried out using a discrete segment model. The detector channel is divided into equal segments with the same amount of reagent R in each segment. The sample moves into the channel in steps corresponding to segments of the same size as the detector segment. Each sample segment contains analyte A at C mole ratio to reagent R. Assuming a stoichiometric ratio of 1:1 for reaction between A and R, there will be formation of only one product band in each detector segment. By examining the number of bands (n) formed after N steps, a set of linear algebraic equations is derived to determine the number of bands (n) for any integer values of N and C. By extrapolating this result to real positive numbers, we obtain the equation L=a.C_A/(b + C_A), where L represents the band length, and C_A represents the concentration/amount of analyte. The equation represents a rectangular hyperbola.

A spectrophotometric method that is sensitive, easy, accurate, exact, reproducible, and verified has been developed for quantifying a new antiepileptic medication called retigabine in both its pure form and pharmaceutical formulations. The techniques employ N-bromosuccinimide (NBS) as an oxidizing agent and three dyes, namely amaranth, methylene blue, and indigo carmine. The three methods rely on the oxidation reaction of retigabine with an excess of N-bromosuccinimide (NBS) in an acidic environment. The unreacted NBS is then quantified by reacting it with fixed amounts of dyes, specifically amaranth, methylene blue, and indigo carmine. The absorbance at 520 nm, 664 nm, and 610 nm is measured for each respective dye. Linear relationships with high correlation coefficients (0.9992-0.9997) were observed under optimal conditions across concentration ranges of 0.5-12, 0.5-16, and 0.5–10 µg/ml. The limit of detection (LOD) for amaranth, methylene blue, and indigo carmine methods were determined to be 0.15, 0.15, and 0.14 µg/ml, respectively. The accuracy and precision of the approaches have been assessed for both intra-day and inter-day measurements. There was no observable interference caused by the typical tablet excipients. The proposed methodologies were verified in compliance with ICH recommendations and effectively utilized for the analysis of retigabine in pharmaceutical formulations. The reliability of the approaches was confirmed by conducting recovery studies employing the usual addition method. The findings produced by the proposed methods were statistically compared to those of the described approach using the student's t-test and F-test, which showed a significant level of agreement.

This paper seeks to improve through esterification the efficiency of triethanolamine (TEA) molecules used in the cement grinding industry. The unmodified and modified-TEAs are tested at 0.025 % to 0.1 % rates to determine their effect on clinker grindability and cement properties including fineness, flow, zeta potential, morphology, rheology, setting, and compressive strength. Test results showed that the esterification reactions performed to modify the TEA hydroxyl groups can remarkably increase their adsorption potentials onto the clinker grains, which reduces the agglomeration phenomenon and grinding energy consumption by 6 % to 13 %. The TEA modified using medium hydrocarbon chain lengths (4–8 carbons) of mono-carboxylic acid compounds performed better than the one containing short hydrocarbon chain lengths (1–3 carbons). The pastes and mortars prepared using the modified-TEA cements exhibited significantly higher fluidity, better compatibility with polycarboxylate-based superplasticizer, and increased strengths than the equivalent mixtures made using cement ground using the unmodified TEA molecules.