Acetonitrile, a polar molecule that cannot form hydrogen bonds on its own, interacts with solvent molecules mainly through the lone pair of its nitrogen atom and the π electrons of its CN triple bond [Correction added on 17 July 2024, after first online publication: Acetole has been changed to Acetonitrile in the preceeding sentence.]. Interestingly, acetonitrile exhibits an unexpected strengthening of the triple bond\'s force constant in an aqueous environment, leading to an upshift (blueshift) in the corresponding stretching vibration: this effect contrasts with the usual consequence of hydrogen bonding on the vibrational frequencies of the acceptor groups, that is, frequency redshift. This investigation elucidates this phenomenon using Raman spectroscopy to examine the behavior of acetonitrile in organic solvent, water, and silver ion aqueous solutions, where an even more pronounced upshift is observed. Raman spectroscopy is particularly well suited for analyzing aqueous solutions due to the minimal scattering effect of water molecules across most of the vibrational spectrum. Computational approaches, both static and dynamical, based on Density Functional Theory and hybrid functionals, are employed here to interpret these findings, and accurately reproduce the vibrational frequencies of acetonitrile in different environments. Our calculations also allow an explanation for this unique behavior in terms of electric charge displacements. On the other hand, the study of the interaction of acetonitrile with water molecules and metal ions is relevant for the use of this molecule as a solvent in both chemical and pharmaceutical applications.

The quality of animal feed is increasingly affected by weather conditions, high humidity, and damage to grains, which have led to various mycotoxin-producing moulds. The aim of this study was to determine the effects of the combination of deepoxy-deoxynivalenol and beta-zearalenol on the development of preimplantation bovine embryos, the extent to which the presence of both mycotoxin metabolites affects the development of in vitro cultured bovine embryos, or whether the effect of both toxins enhances embryotoxicity. Ovaries were transported from the abattoir to the laboratory and, after maturation and fertilisation, zygotes were placed in an embryo culture medium (IVC) with different mycotoxin metabolite concentrations diluted in acetonitrile. It was found that the blastocyst rate of cleaved embryos was affected by 1 μL acetonitrile in 400 μL medium (0.25%) compared to the group without acetonitrile. For this reason, it was decided to use acetonitrile as a control group, and the desired mycotoxin metabolite concentrations were diluted in the lowest possible amount of acetonitrile (0.5 μL) that could be accurately added to the study groups. There was no statistical difference when the higher mycotoxin metabolite concentrations were added.

Pollen collected by pollinators can be used as a marker of the foraging behavior as well as indicate the botanical species present in each environment. Pollen intake is essential for pollinators\' health and survival. During the foraging activity, some pollinators, such as honeybees, manipulate the collected pollen mixing it with salivary secretions and nectar (corbicular pollen) changing the pollen chemical profile. Different tools have been developed for the identification of the botanical origin of pollen, based on microscopy, spectrometry, or molecular markers. However, up to date, corbicular pollen has never been investigated. In our work, corbicular pollen from 5 regions with different climate conditions was collected during spring. Pollens were identified with microscopy-based techniques, and then analyzed in MALDI-MS. Four different chemical extraction solutions and two physical disruption methods were tested to achieve a MALDI-MS effective protocol. The best performance was obtained using a sonication disruption method after extraction with acetic acid or trifluoroacetic acid. Therefore, we propose a new rapid and reliable methodology for the identification of the botanical origin of the corbicular pollens using MALDI-MS. This new approach opens to a wide range of environmental studies spanning from plant biodiversity to ecosystem trophic interactions.

Raman spectroscopy allows for the unambiguous identification of materials through the inelastic scattering of light. This technique has a great many uses in various aspects of society from academic, scientific, and industry. This paper explores a specific type of Raman spectrometer called a spatial heterodyne Raman spectrometer (SHRSy), which is a variation of an interferometric spectrometer. It utilizes a Michelson interferometer and replaces the mirrors with gratings that transform it from a time-domain spectrometer to a spatial-domain spectrometer, allowing for the entirety of the spectrum to be captured at once. This study specifically tests a half-inch two-grating monolithic SHRS (½-in. 2g-mSHRS), which has a weight of <60 g and a size of 2.2 × 2.2 × 1.3 cm. To do this we excite a variety of organic liquids with a 532 nm neodymium-doped yttrium aluminum garnet (Nd:YAG) pulsed laser, using an excitation energy of 6.5 mJ/pulse and distance of 3 m in conjunction with an intensified charge-coupled device camera. This is the first time that the SHRS has been used for investigating polarized Raman spectra of liquids. We discuss and contrast the instrumental properties such as resolution, spectral range, étendue, and field of view with previously tested mSHRS to give context to the instrument\'s performance.

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are associated with amyloid-β (Aβ) plaques and exhibit altered biochemical properties in human Alzheimer\'s disease (AD), as well as in the transgenic 5XFAD mouse model of AD amyloidosis. In the brains of the 5XFAD mouse model devoid of BChE enzyme (5XFAD/BChE-KO), incubation of tissue sections with exogenous BChE purified from human plasma (pl-BChE) leads to its association with Aβ plaques and its biochemical properties are comparable to those reported for endogenous BChE associated with plaques in both human AD and in 5XFAD mouse brain tissue. We sought to determine whether these observations in 5XFAD/BChE-KO mice also apply to human brain tissues. To do so, endogenous ChE activity in human AD brain tissue sections was quenched with 50 % aqueous acetonitrile (MeCNaq) leaving the tissue suitable for further studies. Quenched sections were then incubated with recombinant AChE (r-AChE) or pl-BChE and stained for each enzymes\' activity. Exogenous r-AChE or pl-BChE became associated with Aβ plaques, and when bound, had properties that were comparable to the endogenous ChE enzymes associated with plaques in AD brain tissues without acetonitrile treatment. These findings in human AD brain tissue extend previous observations in the 5XFAD/BChE-KO mouse model and demonstrate that exogenously applied r-AChE and pl-BChE have high affinity for Aβ plaques in human brain tissues. This association alters the biochemical properties of these enzymes, most likely due a conformational change. If incorporation of AChE and BChE in Aβ plaques facilitates AD pathogenesis, blocking this association could lead to disease-modifying approaches to AD. This work provides a method to study the mechanism of AChE and BChE interaction with Aβ plaque pathology in post-mortem human brain tissue.

In this study, a carbon fiber microelectrode (CF) was applied for the investigation of the electrochemical behavior of the natural antioxidant, apocynin (APO). Given the limited solubility of APO in water, a mixture of anhydrous acetic acid (AcH) with 20%, v/v acetonitrile (AN) and 0.1 mol L-1 sodium acetate (AcNa) was used. The electrochemical properties of APO were examined through linear sweep voltammetry (LSV), differential pulse voltammetry (DPV), and cyclic voltammetry (CV). The anodic oxidation of APO, which is the basis of the method used, proved to be diffusion-controlled and proceeded with a two-electron and one proton exchange. Both radicals and radical cations, arising from the first and second step of electrode reactions, respectively, underwent subsequent chemical transformations to yield more stable final products (EqCiEiCi mechanism). Using optimized DPV conditions, the anodic peak current of APO at a potential of 0.925 V vs. Ag/AgCl showed a good linear response within the concentration range of 2.7 × 10-6-2.6 × 10-4 mol L-1. The detection and quantification limits were determined as 8.9 × 10-7 and 2.7 × 10-6 mol L-1, respectively. The developed DPV method enabled the successful determination of APO in herbal extracts and in dietary supplements. It should be noted that this is the first method to be used for voltammetric determination of APO.

Photochemistry of the (n-Bu4N)2[Pt(NO3)6] complex in acetonitrile was studied by means of stationary photolysis and nanosecond laser flash photolysis. The primary photochemical process was found to be an intramolecular electron transfer followed by an escape of an •NO3 radical to the solution bulk. The spectra of two successive Pt(III) intermediates were detected in the microsecond time domain, and their spectral and kinetic characteristics were determined. These intermediates were identified as PtIII(NO3)52- and PtIII(NO3)4- complexes. Disproportionation of Pt(III) species resulted in formation of final Pt(II) products.

To investigate the solvent effect on the detection of peptides and proteins, nanoelectrospray mass spectra were measured for mixtures of 1 % acetic acid and 5 × 10-6 M gramicidin S (G), ubiquitin (U), and cytochrome c (C) in water (W), methanol (MeOH), 1-propanol (1-PrOH), acetonitrile (AcN), and 2-propanol (2-PrOH). Although doubly protonated G (G2+) and multiply protonated U (Un+) and C (Cn+) were readily detected with a wide range of mixing ratios of W solutions for MeOH, 1-PrOH, and AcN, Cn+ was totally suppressed for the solutions with mixing ratios (v/v) of W/2-PrOH (50/50) and (70/30). However, denatured Cn+ started to be detected with W/2-PrOH (90/10) together with Gn+ (n = 1, 2) and native Un+ (n = 6-8). At the mixing ratio of W/2-PrOH (95/5), native Cn+ (n = 7-10) together with Gn+ (n = 1, 2) and native Un+ (n = 6-8) were detected with high ion intensities. The use of W/2-PrOH (95/5) is profitable because it enables the detection of native proteins with high detection sensitivities.

Following previous studies, the ternary mixture of methanol/formamide/acetonitrile (MeOH/Formamide/MeCN) was studied using the UV-Vis absorption spectra at 298.15 K with a set of five probes, 4-nitroaniline, 4-nitroanisole, 4-nitrophenol, N,N-dimethyl-4-nitroaniline and 2,6-diphenyl-4-(2,4,6-triphenyl-1-pyridinio)phenolate (Reichardt betaine dye), for a total of 22 mole ternary fractions. In addition, nine mole fractions of the underling binary mixtures, MeOH/Formamide and Formamide/MeCN were also tested. Spectroscopic results were used to model the preferential solvation order for each probe in the mixtures. The Kamlet-Taft solvatochromic solvent parameters, α, β, and π*, were also computed through the use of the solvatochromic shifts of the five probe indicators. Moreover, discrepancies in the spectroscopic behavior of 4-nitrophenol in formamide-rich mixtures were observed and analyzed.

Acetonitrile wastewater is difficult to treat due to its high salinity and toxicity to microorganisms. In this paper, a micro electro-activated carbon fiber coupled system (ME-ACF) was established to treat simulated acetonitrile wastewater. In the 200 ml system, the concentration of acetonitrile adsorbed by ACF was 91.3 mg/L, while that of acetonitrile adsorbed by ME-ACF was 150.6 mg/L, and the removal efficiency was increased by 65 % in comparison. The activated carbon fibers before and after the reaction were subjected to a series of characterization, and it was found that the SABET decreased from 1393.48 m2/g to 1114.93 m2/g and 900.23 m2/g, respectively, but the oxygen on the surface of the activated carbon fibers was increased, and the effect of the micro electrolytic system on the activated carbon fibers was then analyzed. The possible reasons for the formation of acetic acid contained in the products were also discussed using DFT simulations. The removal mechanism of acetonitrile by ME-ACF was considered to be electrically enhanced adsorption and electro-catalytic hydrolysis.