Acetonitrile Research Articles

Rapid Development and Validation of Atoltivimab, Maftivimab and Odesivimab in Pharmaceutical Dosage form by using the RP-HPLC Method

Background: The reverse-phase high-performance liquid chromatography (RP-HPLC) method was developed for the quantitative measurement of monoclonal antibodies (Maftivimab, Atoltivimab, and Odesivimab) in the pharmaceutical dosage form. The Food and Drug Administration (FDA) has approved these monoclonal antibodies for the treatment of Zaire ebolavirus infection in adults Methods: Maftivimab, Atoltivimab, and Odesivimab were separated chromatographically on the Waters Alliance-e2695 platform using the Luna Phenyl Hexyl (250 x 4.6 mm, 5 μm) column and a mobile phase made up of Acetonitrile (ACN) and ortho-phosphoric acid (OPA) buffer in a ratio of 70:30 (v/v). Results: The flow rate was 1.0 ml/min, and a photodiode array (PDA) detector operating at room temperature was used to measure absorption at 282 nm. For Maftivimab, Atoltivimab, and Odesivimab, the theoretical plates were not less than 2000, and the tailing factor shouldn't be greater than 2, accordingly. All measurements have a constant relative standard deviation of peak areas that is less than 2.0. Conclusion: The suggested procedure was approved following the International Conference on Harmonisation (ICH) recommendations. When used for the quantitative analysis of Maftivimab, Atoltivimab, and Odesivimab, the approach was found to be straightforward, affordable, appropriate, exact, accurate, and robust.

Reduced Surface Trap States of PbS Quantum Dots by Acetonitrile Treatment for Efficient SnO2-Based PbS Quantum Dot Solar Cells.

The solution-phase ligand-exchange strategy offers a simple pathway to prepare PbS quantum dots (QDs) and their corresponding solar cells. However, the production of high-quality PbS QDs with reduced surface trap state density for efficient PbS QD solar cells (QDSCs) still faces challenges. As the hydroxyl group (-OH) has been demonstrated to be the primary source of the surface trap states on PbS QDs in the general oleic acid method, here, we present an effective and facile strategy for reducing the surface -OH content of PbS QDs by using acetonitrile (ACN) as precipitant to wash the surface of QDs, which significantly decreases the trap state density and enables the preparation of superior PbS QDs. The resulting solar cell with an ITO/SnO2/n-PbS/p-PbS/Au structure obtained an improved photoelectric conversion efficiency (PCE) from 8.53 to 10.49% with an enhanced air storage stability, realizing a high PCE for SnO2-based PbS QDSCs.

Combined thermodynamic and theoretical study on ether-functionalized ionic liquid mixture systems of [MOEmim][TFSI] with ACN/GBL

Ether-functionalized ionic liquids (ILs) have a higher fluidity and are widely used in a variety of applications due to the introduction of the ether group. In order to better understand the relationship between properties and internal interactions of ether-based ILs, we prepared two ether-functionalized ILs 1–2-methoxyethyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide ([MOEmim][TFSI]) with acetonitrile (ACN) or γ-butyrolactone (GBL) mixture systems, and investigated the changes of their thermodynamic properties and internal interaction behaviors over the entire concentration range. First, the thermodynamic properties such as dynamic viscosity, density and electrical conductivity of the two mixture systems were measured from 288.15 K to 343.15 K. The excess molar volume (VE), and viscosity deviation (Δη) were calculated by using the measured experimental density and dynamic viscosity data, which can provide microscopic information on the interactions. Further, the intermolecular interactions of the mixture systems were evaluated by density functional theory (DFT) calculations. The sigma–profile (σ–profile) provided insight into the hydrogen bonds (H-bonds) and molecular surfaces interactions. We also used molecular dynamics simulations (MD) to study ILs mixtures in many different solvent concentrations, thereby providing a microscopic and macroscopic characterization of fluid structure, molecular aggregation, and intermolecular forces.

Thermodynamics of complex formation of silver(I) with substituted pyridines and cyclic amines in non-aqueous solvents

The understanding of the thermodynamic stability and speciation of metal complexes in solution requires access to their enthalpy and entropy of formation. In this work, we specifically focus our investigation on the complexation process of silver(I) ion in acetonitrile (AN) with substituted mono pyridines and cyclic monoamines. The aim of this study is to provide reliable thermodynamic data to obtain insights on metal complex formation, focusing on ligands donor properties and solvation effects. Carefully designed potentiometric and calorimetric experiments allowed to define the species present at different ligand/metal ratios and to obtain the complex formation constants and enthalpies. In general, the enthalpy terms associated with the complex formation are highly exothermic, while the entropy values are always unfavorable. The formation constants of AgLj species for the ligands investigated in AN are compared with those previously obtained in dimethyl sulfoxide (DMSO) and water. The trends in stability constants and enthalpy values are discussed in relation to the pKa data available in the different solvents. Higher pKa values correspond to greater ligand basicity and result in more stable and more enthalpy stabilized complexes.

Retention modeling of therapeutic peptides in sub‐/supercritical fluid chromatography

AbstractChromatographic modeling software packages are valuable tools during method optimization steps. These are well established for reversed‐phase applications utilizing retention time (RT) prediction to optimize separations and receive robust methods, which is of high interest for the analysis of pharmaceuticals. In contrast to liquid chromatography, the knowledge of RT prediction in supercritical fluid chromatography is limited to a manageable number of studies.This study uses the software DryLab to predict the RTs of the peptides bacitracin (Bac), colistin, tyrothricin (Tyro), and insulin analogs. Gradient time, column temperature, and the ternary composition (terC) of carbon dioxide, methanol (MeOH), and acetonitrile (ACN) in the gradient elution are varied in a feasibility approach using a neutral (Viridis BEH) and an amino‐derivatized aromatic (Torus 2‐PIC) stationary phase. In the second part, chromatographic optimization is performed in silico through gradient adjustments to optimize the separation of the fingerprint of Bac. The final gradient method utilizes a Viridis BEH column (100 × 3.0 mm, 1.7 μm), carbon dioxide, and a modifier consisting of ACN/MeOH/water/methanesulfonic acid (60:40:2:0.1, v:v:v:v). In addition, changes in the retention order of Tyro compounds with the proportion of the terC in combination with a Torus Diol column are investigated.

Top-Down Exfoliation Process Constructing 2D/3D Heterojunction toward Ultrapure Blue Perovskite Light-Emitting Diodes.

3D perovskites with low energy disorder and high ambipolar charge mobility represent a promising solution for efficient and bright light-emitting diodes. However, the challenges of regulating the nanocrystal size to trigger the quantum confinement effect and control the surface trap states to reduce charge loss hinder the applications of 3D perovskites in blue perovskite light-emitting diodes (PeLEDs). In this study, we present a top-down exfoliation method to obtain blue 3D perovskite films with clipped nanocrystals and tunable bandgaps by employing methyl cyanide (MeCN) for post-treatment. In this method, the MeCN solvent exfoliates the surface components of the 3D perovskite grains through a partial dissolution process. Moreover, the dissolved precursor can be further utilized to construct an ingenious 2D/3D heterostructure by incorporating an organic spacer into the MeCN solvent, contributing to efficient defect passivation and improved energy transfer. Consequently, efficient PeLEDs featuring ultrapure blue emission at 478 nm achieve a record external quantum efficiency of 12.3% among their 3D counterparts. This work emphasizes the significance of inducing the quantum confinement effect in 3D perovskites for efficient blue PeLEDs and provides a viable scheme for the in situ regulation of perovskite crystals.

HPLC Method Development and Validation for the Determination of Apixaban and Clopidogrel in Novel Fixed-Dose Combination Tablets

A simple, fast, and accurate high-performance liquid chromatographic (HPLC) method is developed, optimized, and validated for a fixed-dose combination of apixaban (APX) and clopidogrel (CLOP) tablets according to ICH guidelines. Chromatographic separation of the drugs was performed on a BDS Hypersil C18 (4.6 ∗ 150 mm, 5 μm), with acetonitrile (ACN) and trifluoroacetic acid (TFA) in the ratio 48 : 52 (v/v) as a mobile phase, at a flow rate of 0.9 ml/min., injection volume of 5 μL, and column temperature 45°C. The proposed method was linear over the level 25–200% for a concentration of APX 5 μg/ml and CLOP 75 μg/ml (R2 > 0.999). The detection limit for APX and CLOP was found to be 0.3465 and 3.8496 μg/ml, whereas the quantification limit was 1.0499 and 11.6656 μg/ml, respectively. The recovery was more than 99% using the standard addition method. The developed method was found to be specific, accurate, precise, and robust against changes in column temperature (±5°C) and mobile phase composition (±5% ACN); hence, it can be used for the determination of APX and CLOP in the fixed-dose combination tablets.

Solvent effect on the detection of peptides and proteins by nanoelectrospray ionization mass spectrometry: Anomalous behavior of aqueous 2-propanol

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.

Volatile Perovskite Precursor Ink Enables Window Printing of Phase-Pure FAPbI3 Perovskite Solar Cells and Modules in Ambient Atmosphere.

Despite the great success of perovskite photovoltaics in terms of device efficiency and stability using laboratory-scale spin-coating methods, the demand for high-throughput and cost-effective solutions remains unresolved and rarely reported because of the complicated nature of perovskite crystallization. In this work, we propose a stable precursor ink design strategy to control the solvent volatilization and perovskite crystallization to enable the wide speed window printing (0.3 to 18.0 m/min) of phase-pure FAPbI3 perovskite solar cells (pero-SCs) in ambient atmosphere. The FAPbI3 perovskite precursor ink uses volatile acetonitrile (ACN) as the main solvent with DMF and DMSO as coordination additives is beneficial to improve the ink stability, inhibit the coffee rings, and the complicated intermediate FAPbI3 phases, delivering high-quality pin-hole free and phase-pure FAPbI3 perovskite films with large-scale uniformity. Ultimately, small-area FAPbI3 pero-SCs (0.062 cm2 ) and large-area modules (15.64 cm2 ) achieved remarkable efficiencies of 24.32 % and 21.90 %, respectively, whereas the PCE of the devices can be maintained at 23.76 % when the printing speed increases to 18.0 m/min. Specifically, the unencapsulated device exhibits superior operational stability with T90 >1350 h. This work represents a step towards the scalable, cost-effective manufacturing of perovskite photovoltaics with both high performance and high throughput.

Volatile Perovskite Precursor Ink Enables Window Printing of Phase‐Pure FAPbI3 Perovskite Solar Cells and Modules in Ambient Atmosphere

AbstractDespite the great success of perovskite photovoltaics in terms of device efficiency and stability using laboratory‐scale spin‐coating methods, the demand for high‐throughput and cost‐effective solutions remains unresolved and rarely reported because of the complicated nature of perovskite crystallization. In this work, we propose a stable precursor ink design strategy to control the solvent volatilization and perovskite crystallization to enable the wide speed window printing (0.3 to 18.0 m/min) of phase‐pure FAPbI3 perovskite solar cells (pero‐SCs) in ambient atmosphere. The FAPbI3 perovskite precursor ink uses volatile acetonitrile (ACN) as the main solvent with DMF and DMSO as coordination additives is beneficial to improve the ink stability, inhibit the coffee rings, and the complicated intermediate FAPbI3 phases, delivering high‐quality pin‐hole free and phase‐pure FAPbI3 perovskite films with large‐scale uniformity. Ultimately, small‐area FAPbI3 pero‐SCs (0.062 cm2) and large‐area modules (15.64 cm2) achieved remarkable efficiencies of 24.32 % and 21.90 %, respectively, whereas the PCE of the devices can be maintained at 23.76 % when the printing speed increases to 18.0 m/min. Specifically, the unencapsulated device exhibits superior operational stability with T90>1350 h. This work represents a step towards the scalable, cost‐effective manufacturing of perovskite photovoltaics with both high performance and high throughput.

Novel electrolyte assisted ultralow-temperature zinc battery

Secondary battery is an indispensable component in energy storage as it can uninterruptedly store the energy and release it when being required. Among them, zinc (Zn) rechargeable battery gains much attention due to its cost advantage. However, poor climate adaptation much weaken the competitiveness, and temperature-induced deterioration can be mainly blamed on the slow reaction-kinetics of Zn anode under low temperature. Under this scenario, an anti-freezing electrolyte with Zinc (II)Bis(trifluoromethanesulfonyl)imide (Zn(TFSI)2) salt and ternary solvents of acetonitrile (AN), methyl acetate (MA) and dichloromethane (DCM) is proposed. It successfully broadens the working temperature of Zn secondary battery to − 90 °C. The elaborately regulated solvation can ensure smooth ion-transfer in liquid zone, more importantly, it expedites the desolvation without much affecting the interface transportation. With the optimized electrolyte configuration, reversible Zn plating/stripping at ultra-low temperature has been realized. The Zn|polytriphenylamine (PTPAn) battery thus can reserve 70 % capacity at − 80 °C, and present extremely stable cycling and impressive rate capability at − 80 °C and − 60 °C. The results well address the kinetics issues encountered in the low-temperature Zn secondary battery, and reveals that only with appropriate solvation, the high ion-permeability of the interface as well as easy de-solvation can be guaranteed. The work provides a guideline for designing advanced electrolyte, and supplies a reliable and effective strategy for the all-weather electrochemical energy storage.

The effect of polarity and hydrogen bonding on the electronic and vibrational structure of the salicylate anion in acetonitrile and water: implicit and explicit solvation approaches.

This study investigates the fluorescence quenching of the salicylate anion in water compared to acetonitrile (ACN) and the stability of its keto structure in ACN using DFT and TD-DFT methods at the 6-311++G(d,p) basis set. Computational simulations in implicit and explicit environments of ACN and water reveal the effects of solvent polarity and hydrogen bonding on enol [Od-H⋯Oa] and keto [Od⋯H-Oa] tautomerization, fluorescence quenching, and the spectral profile of the salicylate anion. Implicit solvation models show a barrier height of approximately 1.9 kcal mol-1 in ACN and 3.6 kcal mol-1 in water for enol-keto tautomerization in the ground state, with no barrier in the excited state, leading to an ESIPT reaction in both solvents, but only ground state proton transfer in ACN. Simulated absorption spectra for both enol and keto forms are similar in both solvents, while the emission spectrum is red-shifted in water. Explicit solvation studies indicate greater stabilization of the salicylate anion in water than in ACN, with a blue shift in absorption and emission spectra and varying oscillator strengths. Solvent molecule positioning affects enol-keto stabilization in the ground state, but only the keto structure is stabilized in the excited state. Simulated IR spectra in water show a blue shift in Od-H stretching frequency and increased water molecule vibrational frequencies, suggesting non-radiative excitation energy transfer from salicylate ions to water molecules via n → σ* intermolecular hydrogen bonding interactions. This mechanism explains the fluorescence quenching observed in water and results align with experimental data, indicating hydrogen-bonded keto form stabilization both in water and ACN.

Subsequent bilateral key comparison study - organic solvent calibration solution - gravimetric preparation and value assignment of aflatoxin B1 (AfB1) in acetonitrile (ACN)

Main textThe original CCQM-K154.b comparison was coordinated by the Bureau International des Poids et Mesures (BIPM) and the Chinese National Institute of Metrology (NIM) on behalf of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) for National Measurement Institutes (NMIs) and Designated Institutes (DIs) which provide measurement services in organic analysis under the 'Comité International des Poids et Mesures' Mutual Recognition Arrangement (CIPM MRA) and/or have participated in the BIPM's Mycotoxin Metrology Capacity Building and Knowledge Transfer (MMCBKT) project as part of its "Metrology for Safe Food and Feed in Developing Economies" Capacity Building Programme.Gravimetrically-prepared solutions having an assigned mass fraction of specified organic analytes are routinely used to calibrate measurement processes for the quantification of the same analytes in matrix samples. Appropriate assignments of the property value and associated uncertainty of calibration solutions thus underpin the traceability of routine analysis and are critical for accurate measurements. Evidence of successful participation in relevant international comparisons is needed to document calibration and measurement capability claims (CMCs) made by national metrology institutes and designated institutes. In total, eleven NMIs/DIs participated in the Track C, Model II, Key Comparison CCQM-K154.b [Gravimetric preparation and value assignment of aflatoxin B1 (AfB1) in acetonitrile (ACN)] for emerging areas of global interest and innovation. Participants were requested to gravimetrically prepare calibration solutions and value assign the mass fractions, expressed in mg/kg, of aflatoxin B1 (AfB1) in the acetonitrile (ACN) solution. Study samples, with assigned values and associated uncertainties were prepared by the comparison participants and sent to the coordinating laboratory for comparison. The Key Comparison Reference Values (KCRVs), calculated form values measured by the coordinating laboratory based on calibrations obtained from independent gravimetrically prepared calibrant solutions, agreed with participants reported values, within their stated uncertainties.AfB1 was selected to be representative of polar aflatoxins. Aflatoxins are a class of mycotoxins generally produced by fungi of the genus Aspergillus. It was anticipated to provide a challenge representative for the gravimetrical preparation and value assignment of calibration solutions in the mass fraction range of 2 mg/kg to 50 mg/kg of mycotoxins with broadly similar structural characteristics.In the original study CCQM-K154.b, nine participants of the MMCBKT programme were provided with a stock solution having a known AfB1 mass fraction and expanded uncertainty to use to gravimetrically prepare and value assign a calibration solution. Three NMIs/DIs also participated using their own calibration solutions. The use of in-house solutions required anadditional capacity to undertake a fit-for-purpose purity assessment. NIM was the only NMI participating using both the MMCBKT based and their own in-house assigned solutions in order to connect the two different groups.It was decided to propose separate KCRVs for each of the two ampoules provided by the participating NMIs/DIs based on the AfB1 mass fraction. This allowed participants to demonstrate the efficacy of their implementation of the approaches used to gravimetrically prepare calibrations solutions and to assess the AfB1 mass fraction.The majority of the AfB1 mass fraction KCRVs (wKCRV) for CCQM-K154.b spanned a mass fraction range of 2.02 mg/kg to 31.57 mg/kg. The relative expanded uncertainties U(wKCRV) ranged from 0.69 % to 2.93 %. Inspection of the degree of equivalence plots for the AfB1 mass fraction assignments in CCQM-K154.b indicated that there was an excellent agreement of results. Solely, the AfB1 mass fraction assignments of the INRAP (Institut National de Recherche et d'Analyse Physico-Chimique, Tunisia) did not agree with the KCRVs. It was found that the samples were altered as a result of an acid contamination.The INRAP has produced a new batch of AfB1 calibration solution using the AfB1 stock solution originally provided to MMCBKT participants to be able to demonstrate the efficacy of their implementation of the approaches used to gravimetrically prepare calibrations solutions and to assess the AfB1 mass fraction. The BIPM organized the present subsequent bilateral comparison CCQM-K154.b.1 to assess the new batch of AfB1 calibration solution of the INRAP. Inspection of the degree of equivalence plots for the AfB1 mass fraction assignments indicated that there is an excellent agreement of the INRAP results for CCQM-K154.b.1.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Quick and Concise Nonaqueous Capillary Electrophoresis Approach for Simultaneous Separation and Determining Five Phytohormones

A new, quick and concise nonaqueous capillary electrophoresis approach has been matured to separate phytohormones involving indobutyric acid, indoleacetic acid, abscisic acid, 1-naphthaleneacetic acid and gibberellin. Using a running buffer composed of 85% methyl cyanide, 0.8% 1.0 M caustic soda and 20.0 mM methanol ammonium acetate, satisfactory separation of five phytohormone standards was achieved within 4 mins. The lowest detection limit was obtained for 1-naphthaleneacetic-acid (0.06 and#181;g/ml) and the highest for gibberellin (1.71 and#181;g/ml). The approach has been utilized for wheat bud samples with spiked 5 phytohormones using a solid phase extraction procedure, acquiring recovery percentage ranging from 95 to 102%.

Synthesis, characterization, crystal structure, and fabrication of photosensitive Schottky device of a binuclear Cu(ii)-Salen complex: a DFT investigations.

This work explores one centrosymmetric binuclear Cu(ii)-Salen complex synthesis, characterization, photosensitive Schottky barrier diode (PSBD) function, and DFT spectrum. The crystal growth involves H2LSAL and Cu(NO3)2·3H2O in CH3OH + ACN (acetonitrile) solvent medium. Herein, structural characterization employs elemental, IR/Raman, NMR, UV-VIS, DRS, SEM-EDX, PXRD, SCXRD, and XPS analyses. The complex crystal size is 0.2 × 0.2 × 0.2, showing monoclinic space group C2/c. The dimeric unit contains two Cu(ii) centres with distorted square pyramidal (SQP) geometries. The crystal packing consists of weak C-H⋯O interactions. DFT and Hirshfeld surface (HS) further substantiated the packing interactions, providing valuable insights into the underlying mechanisms. The 2-D fingerprint plots showed the presence of N⋯H (3%) and O⋯H (8.2%) contacts in the molecular arrangement. NBO, QTAIM, ELF-LOL, and energy frameworks are utilized to investigate the bonding features of the complex. We extensively studied electrical conductivity and PSBD for H2LSAL and the complex based on band gap (3.09 and 3.07 eV). Like an SBD, the complex has better electrical conductivity, evidencing potentiality in optoelectronic device applications. Optical response enhances conductivity, according to I-V characteristics. Complex Schottky diode has lower barrier height, resistance, and higher conductivity under light. The complex transports charge carriers through space and is rationalized by the 'hopping process' and 'structure-activity-relationship' (SAR). The charge transport mechanism was analysed by estimating complex mobility (μeff), lifetime (τ), and diffusion length (LD). The experimental and theoretical DOS/PDOS plots provide evidence for the Schottky diode function of the complex.

Development and Validation of a Bioanalytical Method for Estimating Ellagic Acid in Wistar Rat Plasma by RP-HPLC Using a Gradient Elution Technique

Abstract Background: Ellagic acid (EA) is a natural polyphenolic compound recognized for bioactive and pharmacologic properties that is found abundantly in various plant groups, particularly eudicotyledons. In the current study a novel, reliable, and cost-effective bioanalytical method was developed for quantifying EA in Wistar rat plasma using RP-HPLC. Methods: Zorbax SB C18 (5μ, 4.6150 mm) and Ascentis C18 (5μ, 1004.6 mm) columns were used in the stationary phase, while the mobile phase consisted of water with 0.1 % formic acid (A) and acetonitrile (ACN) with 0.08% formic acid (B). Results: Optimized parameters were as follows: temperature, 30°C; flow rate, 1.0 ml/min; and PDA detectors, 254 nm. The method exhibited high linearity (r2 = 0.9993) between 5 and 300 μg/ml. Precision, both intra- and inter-day, was within acceptable limits (relative standard deviation <2%), and the mean recovery was 99.73%. The LOD and LOQ were 1.564 ± 0.026 μg/ml and 5.015 ± 0.025 μg/ml, respectively. Stability tests, including short- and long-term evaluations, demonstrated stability under various conditions. Conclusion: The developed method met the necessary criteria and holds promise for application in clinical laboratories for assessing EA levels, either alone or with analytes.

Sensitive and accurate determination of oil-soluble and water-soluble organosulfur compounds in garlic matrix using reversed phase-high performance liquid chromatography.

Garlic is in the family Liliaceae and has many different constituents such as organic sulfur compounds, amino acids, carbohydrates, minerals, and vitamins. In this work, a simple, sensitive, and accurate analytical method was developed for the determination of selected organosulfur compounds (OSCs) in garlic bulbs using reversed phase-high performance liquid chromatography (RP-HPLC). Oil-soluble and water-soluble OSCs were extracted from the garlic samples via acetonitrile and deionized water, respectively. The OSCs were separated on a Phenomenex C18 (250 mm, 4 mm, 5mm) column and the monitoring was performed with a UV detector at 220 nm. An isocratic mobile phase comprising of 0.10 M trifluoroacetic acid (TFA) in 85% acetonitrile (ACN) and 0.10 M TFA in distilled water (DW) (90: 10% v/v) was used to elute the analytes. Under optimum experimental conditions, the limits of detection (LOD) for the analytes were calculated in the range of 0.09 to 0.17 mg/kg. For the garlic sample extracts analyzed under optimal instrumental conditions, DAS (diallyl sulfide), DADS (diallyl disulfide), and DATS (diallyl trisulfide) were detected in the ranges of 8.0 to 32.5 mg/kg, 20.4 to 67.3 mg/kg, and 60.7 to 356.6 mg/kg, respectively. Spiked recovery experiments were conducted on the garlic samples to confirm the method's applicability and accuracy. The recovery results ranged between 39.0% and 90.9% for the garlic samples extracted with deionized water. The developed method is simple, precise, accurate, reliable, and time-effective for the determination of OSCs. Additionally, the green profile of the developed method was investigated by using AGREEprep software and the greenness score was recorded as 0.65, indicating that the method developed is environmentally friendly.

A chemodosimetric chemosensor for the ratiometric detection of nerve agent-mimic DCP in solution and vapor phases.

Nerve agents are among the most deadly and lethal chemical warfare agents (CWAs). Rapid identification is crucial for specialized individuals to take action against dangerous drugs. This paper describes the synthesis and characterisation of a probe (MNFZ) based on the methoxy naphthalene-furoic hydrazide group. The probe rapidly (100 s) detects and quantifies the nerve-agent simulant diethyl chlorophosphate (DCP) in both solution and vapor phases. This sensor uses a new recognition center, furoic hydrazide, where the nitrogen atom of the imine group (CN) attacks the electrophilic core phosphorus atom of DCP, followed by the hydrolysis of the imine group in the acetonitrile (ACN) solution to produce the corresponding aldehyde MNPA. The development of ICT character resulted in a distinct red-shifted ratiometric fluorescence response to DCP, with a very low limit of detection (12.2 nM). The probe is an efficient chemosensor due to its high selectivity over other organophosphorus compounds as well as its chemical stability across a wide pH range. DFT calculations, 1H NMR and HRMS were performed to finalize the sensing mechanism. Lastly, the as-designed sensor was successfully used to build a highly sensitive portable kit in test strips and a cotton biopolymer for simple and safe real-time monitoring of DCP.

Structure, dynamic, and free energy analyses of 5-hydroxymethylfurfural in aprotic solvents and imidazolium ionic liquids using all-atom molecular dynamics simulations.

5-Hydroxymethylfurfural (5-HMF) is an important chemical generated from lignocellulosic biomass (LCB) to produce a wide variety of value-added chemicals, biofuels, and biochemicals. Different forms of ionic liquids (ILs) have been utilized for the formation of 5-HMF from LCB. However, 5-HMF is highly soluble in imidazolium-based ionic liquids (IMILs), which makes it difficult to separate after its formation from LCB. In this manuscript, we perform all-atom molecular dynamics simulations to investigate the performance of several aprotic solvents in the extraction of 5-HMF from various IMILs. We consider twelve aprotic solvents with different physicochemical properties, such as acetonitrile (AN), acetone (AT), 1,4-dioxane (DI), N,N-dimethyl acetamide (DMA), N,N-dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), gamma-butyrolactone (GBL), gamma-valerolactone (GVL), hexamethylphosphoramide (HMPA), N-methyl pyrrolidone (NMP), propylene carbonate (PC), and sulfolane (SF). We analyze various structures and dynamics and perform a detailed thermodynamic analysis to understand the underlying molecular behavior. The results indicate that solvents AT and DI showed the least favorable interactions with 5-HMF, whereas HMPA showed the most favorable interactions with 5-HMF. Based on the detailed structural insights, HMPA enhances the separation of 5-HMF from the ILs. Furthermore, different anion combinations were tested to benchmark their separation capability. Overall, the results presented in this manuscript guide the selection of solvent and IL combinations for the effective separation of 5-HMF.

Low-frequency (0-450 cm-1) dynamics of n-alkyl cyanide liquids studied by optical Kerr effect spectroscopy and density functional theory.

This article presents a study of the dynamics of n-alkyl cyanides (CnH2n+1CN with n = 1-5) in the 0-450 cm-1 spectral region as a function of alkyl chain length. The spectra were measured using femtosecond optical Kerr effect (OKE) spectroscopy. The OKE spectra are characterized by a broad band in the 0-150 cm-1 region arising mainly from intermolecular modes and by narrow bands in the 150-450 cm-1 region arising from intramolecular modes. The intramolecular bands in the OKE spectra are in good agreement with the bands in simulated spectra obtained from density functional theory calculations. For cyanide molecules with long alkyl chains (n = 3-5), a low frequency intramolecular band associated with a torsional vibrational mode overlaps with the intermolecular band. Applying multicomponent line-shape analysis to the broad low-frequency band allowed us to obtain the intermolecular component of the band. We find the frequency and amplitude of the intermolecular band decrease with increasing chain length. Based on previous theoretical studies of the OKE spectrum of methyl cyanide and OKE reorientational studies of n-alkyl cyanides, we show that the dependence of the frequency of the intermolecular band on alkyl chain length is consistent with the band being primarily due to the hindered rotational motion of the molecules in the extended configuration about an axis perpendicular to the long axis of the molecule. The dependence of the amplitude of the intermolecular band on alkyl chain length is a mass effect associated with suppression of the collision-induced contribution to the intermolecular band.