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•Furfurylamine derived Schiff base ligand was prepared and used as Cd(II) probe.•Tap and lake water analysis.•Limit of detection was found to be 0.2345 μM.
The ability of the new ...furfurylamine-derived Schiff base ligand (E)-4-chloro-2-(((5-methylfuran-2-yl)methyl)imino)methyl)phenol (CFMP) to recognize metal ions as a chemosensor has been studied. According to thorough research on the several facets of metal sensing phenomena, the Schiff base ligand CFMP demonstrated selective colorimetric and fluorescence sensing behavior towards the Cd2+ ion in a methanol–water system with strong binding nature, which was easily visible to the human eye. Job's plot titrations were used to determine the metal–ligand complex's stoichiometry, and LCMS data served as further confirmation. The CFMP has a low detection limit (LOD) of 0.2345 µM and shown outstanding fluorescence sensing activity in buffer fluid with a pH of 7.2. Investigations into the fluorescence characteristics of the CFMP and the metal complex in the solution state revealed an improvement in fluorescence emission intensity following complexation. Additionally, utilizing electronic absorption spectroscopic techniques on samples of lake and tap water, the use of Cd2+ ion detection in real water samples was investigated.
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•Chromone functionalized pyridine chemosensor was synthesized.•CD can selectively detect cupric ions with limit of detection 1.2 × 10-6 M.•The binding stoichiometry obtained as 1:2 ...for CD: Cu2+ complex from Job’s plot.•The Schiff base utilized for sensing cupric ions in a variety of spiked samples of water.
A new Schiff base 2-ethoxy-3-{(6-{(2-ethoxy-4-hydroxy-2H-chromen-3-yl)methylideneamino}pyridine-2-yl)iminomethyl}–2H-chromen-4-ol (CD) was synthesized as a result of the condensation of 2,6-diaminopyridine and 3-formyl chromone in 1:2 M ratio and used for cupric ions detection and characterized through FTIR, HRMS and 1H NMR spectral techniques. The sensing capability of Schiff base for cupric ions as compared to other transition metal ions was examined by absorbance and emission studies. A considerable decrease in emission intensity appeared in Schiff base in the case of cupric ions while irrelevant changes were examined for the rest of the ions. The binding stoichiometry was obtained as 1:2 for CD: Cu2+ complex intended from the job’s plot which was confirmed through HRMS spectral technique. DFT calculations were carried for the confirmation of structural relationships and absorption–emission data. The Regression coefficient, Limit of detection, and Association constant were obtained as 98.7%, 1.2 × 10-6 M, and 3.26 × 104 M−1 respectively using Benesi-Hildebrand (B-H) equation. The sensing power of Schiff base CD to recognize cupric ions was unaltered by the addition of the rest of metal ions, which was authenticated through interference studies. Schiff base CD and its complex with cupric ions were found stable over an extensive time period as revealed by time-reliant studies. The data collected by pH studies revealed that the preferred pH range for detecting cupric ions by Schiff base CD was 6 to 11. The Schiff base was finally utilized for sensing cupric ions in a variety of spiked samples of water like canal water, tap water, groundwater, distilled water.
The design of a building is a collaborative process among experts from multiple disciplines. Using Building Information Modeling (BIM), a model is developed through multiple refinement stages to ...satisfy various design and engineering requirements. Such refinements of geometric and semantic information are described as levels of development (LOD). Thus far, there is no method to explicitly define an LOD’s requirements nor to precisely specify the uncertainties involved. Furthermore, despite the insufficient information in the early design stages, a BIM model appears precise and certain, which can lead to false assumptions and model evaluations, for example, in the case of energy efficiency calculations or structural analyses. Hence, this paper presents a multi-LOD meta-model to explicitly describe an LOD’s requirements, incorporating the potential fuzziness of both, geometric and semantic information of individual elements. The explicitly defined fuzziness can be taken into account when applying simulations or analyses for assessing the performance of different building design variants. To support the continuous elaboration of a building from the conceptual to the detailed design stages, the multi-LOD model makes it possible to ensure the consistency of the geometric and semantic information as well as the topological coherence across the different LODs. The feasibility of the approach is demonstrated by its prototypical implementation as a web-server and user-interface, providing a means for managing and checking the exchange requirements both at the meta-level and for concrete building model instances. The paper is concluded with a case study of a real-world construction project that demonstrates the use of the meta-model to support model analysis and the decision-making process.
Aflatoxins, produced mainly by filamentous fungi
Aspergillus flavus
and
Aspergillus parasiticus
, are one of the most carcinogenic compounds that have adverse health effects on both humans and ...animals consuming contaminated food and feed, respectively. Aflatoxin B1 (AFB1) and aflatoxin B2 (AFB2) as well as aflatoxin G1(AFG1) and aflatoxin G2 (AFG2) occur in the contaminated foods and feed. In the case of dairy ruminants, after the consumption of feed contaminated with aflatoxins, aflatoxin metabolites aflatoxin M1 (AFM1) and aflatoxin M2 (AFM2) may appear in milk. Because of the health risk and the official maximum limits of aflatoxins, there is a need for application of fast and accurate testing methods. At present, there are several analytical methods applied in practice for determination of aflatoxins. The aim of this review is to provide a guide that summarizes worldwide aflatoxin regulations and analytical methods for determination of aflatoxins in different food and feed matrices, that helps in the decision to choose the most appropriate method that meets the practical requirements of fast and sensitive control of their contamination. Analytical options are outlined from the simplest and fastest methods with the smallest instrument requirements, through separation methods, to the latest hyphenated techniques.
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•4,4′-((1E,1′E)-hydrazine-1,2-diylidenebis(methanylylidene))diphenol synthesized.•1:1 inclusion complexes are made with γ-cyclodextrin.•H-bond distance and HOMO-LUMO band gap are ...supports the complexes.•Al3+ sensing activity is observed for the obtained fluorescent probe.•Real sample analysis is also carried out with tap, pond, and sea water.
The 4, 4′- ((1E, 1′E)-hydrazine-1,2-diylidenebis(methanylylidene)) diphenol (4-HBA) is successfully synthesized utilizing 4-hydroxybenzaldehyde (4-HB) and hydrazine hydrate as the starting materials. The synthesized 4-HBA is confirmed by the spectral analysis of 1H NMR, FT-IR, UV–Visible, and HR-Mass spectroscopy. The inclusion complexes of 4-HBA with γ-cyclodextrin are therefore investigated using UV and fluorescence spectroscopy. When γ-CD combined with 4-HBA, a 1:1 inclusion complex (ICs) is created that causes absorption and fluorescence spectral changes. The molecular computational analysis is carried out utilizing PM3 Gaussian software revealing the orientation of the synthetic 4-HBA within the γ-CD cavity. The HOMO-LUMO band gap and the DFT analysis specifically support the ICs, with the help of energy values and the H-bond distance. The hydrophobic contact between the host and guest molecules is strongly supported by the 1H NMR and 2-D NMR data, with the matching Ar-H proton moving to higher chemical shift values and the strong cross-correlation spot validating the conclusion. Al3+ sensing activity is observed using fluorescent probes in conjunction with UV and FL spectral analysis. Other metal ions are present in the solutions even though they are not readily available, most notably the Al3+ that binds to the fluorescent probe. Here, the Al3+ selective responses, the colour changes at the wavelength regions, and a fluorescence microscopic image of the solution media are also shown. The selected metal ions recovery percentage is used to determine the concentrations in a variety of clean water samples, including tap water, pond water, and also sea water.
Poor recovery of phosphorus (P) across natural environment (water, soil, sediment, and biological sources) is causing rapid depletion of phosphate rocks and continuous accumulation of P in natural ...waters, resulting in deteriorated water quality and aquatic lives. Accurate detection and characterization of various P species using suitable analytical methods provide a comprehensive understanding of the biogeochemical cycle of P and thus help its proper management in the environment. This paper aims to provide a comprehensive review of the analytical methods used for P speciation in natural environment by dividing them into five broad categories (i.e., chemical, biological, molecular, staining microscopy, and sensors) and highlighting the suitability (i.e., targeted species, sample matrix), detection limit, advantages-limitations, and reference studies of all methods under each category. This can be useful in designing studies involving P detection and characterization across environmental matrices by providing insights about a wide range of analytical methods based on the end user application needs of individual studies.
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•Analytical methods for P speciation in natural environment comprehensively reviewed.•Detectable species, sensitivity, specificity, and suitable sample matrix of each method discussed.•Advantages and limitations of each method reviewed.•Multiple relevant studies from each method summarized in tabular form.
The iterative and developing nature of designing a building involves the specification and handling of vague, imprecise, and incomplete information. A crucial factor for mitigating the impact of ...these uncertainties on the decision-making process is to effectively quantify and communicate them among the project stakeholders. The interactive visualization of 3D building models provides great support for evaluating building designs. However, the currently available visualization methods of the available authoring tools do not incorporate the potential uncertainties associated with the geometric and semantic information of building elements. Currently, building models appear precise and certain, even in the early design stages, which can lead to false assumptions and model evaluations, affecting the decisions made throughout the design stages. Hence, this paper presents a set of visualization approaches, including intrinsic, extrinsic, animation, and walkthroughs, that have been developed to present the uncertainties associated with the building elements’ information. The efficiency of the approaches developed in this study was evaluated through an online survey and interviews. More specifically, the approaches were compared in terms of intuitiveness, applicability, and acceptance. The evaluation results positively indicated the participants’ ability to understand the amount and impact of the uncertainties on the design by using the developed approaches.
In the Japanese official detection method for unauthorized genetically modified (GM) papayas, one of two types of real-time PCR reagents with DNA polymerase (TaqMan Gene Master Mix TaqMan Gene or ...FastGene QPCR Probe Mastermix w/ROX FastGene) is primarily used for measurement. In 2022, we conducted a laboratory performance study on the unauthorized GM papaya line PRSV-YK, and the results revealed that high threshold cycle (Cq) values for the PRSV-YK detection test were obtained using TaqMan Gene with the 7500 Fast & 7500 Real-Time PCR System (ABI7500) and QuantStudio 12K Flex (QS12K), indicating the possibility of false negatives. The possibility of similar problems with all unauthorized GM papaya lines detection tests needs to be evaluated. In this study, we performed detection tests on unauthorized GM papaya lines (PRSV-YK, PRSV-SC, and PRSV-HN), the cauliflower mosaic virus 35S promotor (CaM), and a papaya positive control (Chy), and examined how the limits of detection (LOD) for each test are affected by two types of DNA polymerases (TaqMan Gene and FastGene) and three types of real-time PCR instruments (ABI7500, QS12K, and LightCycler 480 Instrument II LC480). In the PRSV-YK and PRSV-SC detection tests using ABI7500 and QS12K, measurement with TaqMan Gene showed a higher LOD than FastGene. In this case, an exponential amplification curve was confirmed on the amplification plot; however, the amplification curve did not cross the ΔRn threshold line and the correct Cq value was not obtained with a threshold line=0.2. The other tests (PRSV-HN, CaM, and Chy with ABI7500 and QS12K, and all detection tests with LC480) showed no important differences in the LOD for each test using either DNA polymerase. Therefore, when performing PRSV-YK and PRSV-SC detection tests with the ABI7500 or QS12K, FastGene should be used to avoid false negatives for foods containing GM papaya lines PRSV-YK and PRSV-SC at low mixing levels.
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