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Vibrational spectroscopies play, still today, a crucial role in the non-destructive characterization of material having the most varied origins (e.g., environmental, geological, polymeric, artistic, etc.), and, together with UV/VIS spectroscopy, they represent university students' first approach to spectroscopy. Vibrational spectroscopy may be defi...
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... These functional groups in combination create a unique molecular 'fingerprint' that is instrumental in sample identification and authentication. In FTIR spectroscopy, the mid infrared (4000-400 cm − 1 ) spectral range is commonly used for studying fundamental vibrations and rotational/vibrational properties of molecules [10]. This technique offers several advantages, such as a high signal-tonoise ratio, simultaneous detection of all frequencies, rapid data acquisition, and non-destructive analysis [11,12]. ...
... Raman is another form of vibrational spectroscopy that uses laser beams to interact with materials and operates in the infrared region of the electromagnetic spectrum from 2500 to 25000 nm (Siesler et al., 2008). Though Raman and MIR spectroscopy methods use high levels of energy to detect molecular vibrations, Raman spectroscopy excels at equal vibrations of nonpolar sets, while MIR spectroscopy excels at the unequal vibrations of polar sets (Campanella et al., 2021). Raman spectroscopy consists of a monochromatic laser, wavelength separator, and a detector, as presented in Figure 5 (Qin et al., 2019). ...
The quality of tropical fruits and vegetables and the expanding global interest in eating healthy foods have resulted in the continual development of reliable, quick, and cost-effective quality assurance methods. The present review discusses the advancement of non-destructive spectral measurements for evaluating the quality of major tropical fruits and vegetables. Fourier transform infrared (FTIR), Near-infrared (NIR), Raman spectroscopy, and hyperspectral imaging (HSI) were used to monitor the external and internal parameters of papaya, pineapple, avocado, mango, and banana. The ability of HSI to detect both spectral and spatial dimensions proved its efficiency in measuring external qualities such as grading 516 bananas, and defects in 10 mangoes and 10 avocados with 98.45%, 97.95%, and 99.9%, respectively. All of the techniques effectively assessed internal characteristics such as total soluble solids (TSS), soluble solid content (SSC), and moisture content (MC), with the exception of NIR, which was found to have limited penetration depth for fruits and vegetables with thick rinds or skins, including avocado, pineapple, and banana. The appropriate selection of NIR optical geometry and wavelength range can help to improve the prediction accuracy of these crops. The advancement of spectral measurements combined with machine learning and deep learning technologies have increased the efficiency of estimating the six maturity stages of papaya fruit, from the unripe to the overripe stages, with F1 scores of up to 0.90 by feature concatenation of data developed by HSI and visible light. The presented findings in the technological advancements of non-destructive spectral measurements offer promising quality assurance for tropical fruits and vegetables.
... In short, IR spectroscopy measures the relationship between light and the molecules present in a sample. NIR spectroscopy is based on the measurement of molecular overtones and a combination of vibrational modes (Bec, Grabska, and Huck 2022), while MIR spectroscopy measures the fundamental vibrations that are associated with the functional groups present in the sample that can help in determining the chemical composition and other functional properties of the sample, as well as identify samples using the MIR fingerprint region (Campanella, Palleschi, and Legnaioli 2021). ...
Cruciferous vegetables and oilseeds are rich in glucosinolates that can transform into isothiocyanates upon enzymic hydrolysis during post-harvest handling, food preparation and/or digestion. Vegetables contain glucosinolates that have beneficial bioactivities, while glucosinolates in oilseeds might have anti-nutritional properties. It is therefore important to monitor and assess glucosinolates and isothiocyanates content through the food value chain as well as for optimized crop production. Vibrational spectroscopy methods, such as infrared (IR) spectroscopy, are used as a nondestructive, rapid and low-cost alternative to the current and common costly, destructive, and time-consuming techniques. This systematic review discusses and evaluates the recent literature available on the use of IR spectroscopy to determine glucosinolates and isothiocyanates in vegetables and oilseeds. NIR spectroscopy was used to predict glucosinolates in broccoli, kale, rocket, cabbage, Brussels sprouts, brown mustard, rapeseed, pennycress, and a combination of Brassicaceae family seeds. Only one study reported the use of NIR spectroscopy to predict broccoli isothiocyanates. The major limitations of these studies were the absence of the critical evaluation of errors associated with the reference method used to develop the calibration models and the lack of interpretation of loadings or regression coefficients used to predict glucosinolates.
... The positions of the bands in the spectrum can be presented in wave numbers using the inverse centimeter unit (4000À400 cm 21 ) or in micrometers (2.5À16 μm). The FTIR technique presents many advantages, including the speed of the spectra obtention; it is nondestructible, presents high resolution, and has good reproducibility (Campanella et al., 2021). ...
... However, the resolution required for gas detection (pm-level) is almost three orders of magnitude higher than that for solids and liquids (nm-level). Since molecules in the gaseous state rotate freely, the fine rotational structures can be observed in the form of fine absorption peaks, especially occurring in the simple molecules (a group of atoms held together by covalent bonds) 60 . So far, the gas detection has been widely demanded by industrial applications, including monitoring the hazardous gases for production safety management, detecting the emission of greenhouse gases and volatile organic compounds (VOCs) for environmental protection 61 . ...
The proliferation of Internet-of-Things has promoted a wide variety of emerging applications that require compact, lightweight, and low-cost optical spectrometers. While substantial progresses have been made in the miniaturization of spectrometers, most of them are with a major focus on the technical side but tend to feature a lower technology readiness level for manufacturability. More importantly, in spite of the advancement in miniaturized spectrometers, their performance and the metrics of real-life applications have seldomly been connected but are highly important. This review paper shows the market trend for chip-scale spectrometers and analyzes the key metrics that are required to adopt miniaturized spectrometers in real-life applications. Recent progress addressing the challenges of miniaturization of spectrometers is summarized, paying a special attention to the CMOS-compatible fabrication platform that shows a clear pathway to massive production. Insights for ways forward are also presented.
Phthalic acid esters are integral components of modern plastic products and packaging materials, which causes significant contamination of food products and the environment, leading to the need for simple productive monitoring methods. The article presents a rapid enzyme-linked immunosorbent assay (ELISA) for the determination of dibutyl phthalate (DBP) in fruit juices, based on the competitive interaction between free and bound antigen for the binding sites of specific antibodies. The analytical characteristics of the method were studied in various kinetic regimes of the competition stage. Optimal conditions have been established to ensure the minimum detection limit and high measurement accuracy. The duration of the competitive stage of ELISA was chosen 30 min; the range of determined concentrations of DBP was from 0.37 to 68.34 ng/mL with a detection limit of 0.08 ng/mL. The efficiency of the proposed ELISA for testing fruit juices was shown for the chosen DBP extraction mode.
Lithium‐oxygen batteries show promising energy storage potential with high theoretical energy density; however, further investigation of chemical reactions is required. In this study, experimental Raman and theoretical analyzes are performed for a Li‐O 2 battery with LiClO 4 /dimethyl sulfoxide (DMSO) electrolyte and carbon cathode to understand the role of intermediate species in the reactional mechanism of the cell using a high donor number solvent. Operando Raman results reveal reversible changes in the DMSO bands, in addition to the formation and decomposition of Li 2 O 2 . On discharge, a decrease in DMSO polarizability is observed and bands of DMSO‐Li ⁺ ‐anion interactions are evidenced and supported by ab initio density functional theory (DFT) calculations. Molecular dynamics (MD) force field simulations and operando Raman show that DMSO interacts with LiO 2 (sol), highlighting the stability of the electrolyte compared to the interaction with reactive . On charging, the presence of Li ⁺ indicates the formation of a lithium‐deficient phase, followed by the release of Li ⁺ and oxygen. Therefore, this study contributes to understanding the discharge/charge chemistry of a Li‐O 2 cell, employing a common carbon cathode and DMSO electrolyte. The combination of a simple characterization technique in operando mode and theoretical studies provides essential information on the mechanism of Li‐O 2 system.
This work reports the synthesis and characterization of preceramic- and polymer-derived SiOC aerogels obtained from a commercial siloxane resin. The preceramic aerogels were obtained by ambient pressure drying (ambigels) and CO2 supercritical drying. Despite different drying processes, the final ceramic ambi/aerogels have very similar microstructural features in density, porosity, pore size, and specific surface area. Both materials have shown promising results for oil sorption and water cleaning. Supercritically dried-SiOC aerogel had low thermal conductivity with 0.046 W·m–1·K–1 at RT and 0.073 W·m–1·K–1 at 500 °C. These results suggest that substituting the rather complicated and expensive CO2–SC drying with the more friendly and cheap ambient pressure drying can be done without having to accept significant microstructural/property degradation.
