Aqueous Solution Research Articles

The Phase Equilibria of Natural Gas Hydrate in the Presence of 1,3-Dimethylcyclohexane and Octyl-β-D-glucopyranoside

The thermodynamic effect of octyl-β-D-glucopyranoside (OGP) on the formation of methane-1,3-dimethylcyclohexane (DMCH) hydrate was studied in this work. The thermodynamic equilibrium hydrate formation pressures between 275.15 K and 283.15 K were measured by the isothermal pressure search method. Different OGP aqueous solutions (0, 0.1, and 1 wt%) were used in this work. The experimental results show that OGP had no obvious thermodynamic inhibition on methane-DMCH hydrate formation when its concentration was low (0.1 wt%), whereas it had an inhibition on methane-DMCH hydrate formation when its concentration was high (1 wt%). The phase equilibrium hydrate formation pressure of the methane-DMCH-OGP system is about 0.1 MPa higher than that of the methane-DMCH system. The dissociation enthalpies of methane hydrate in different solutions remained uniform, which indicates that OGP was not involved in methane-DMCH hydrate formation. This phenomenon is explained from the perspective of the molecular structure of OGP. As a renewable and biological nonionic surfactant, the concentration of OGP in the liquid phase is low, so OGP can be added to the methane-DMCH system without significant thermodynamic inhibition.

Influence of nicotinic acid additive on the electrodeposition of nickel from aqueous solution

In nickel-plating aqueous baths, both organic and inorganic additives are employed to enhance surface finish, reduce roughness, and achieve a uniform morphology of the coatings. This study investigates how four different concentrations of nicotinic acid (NA) additive, combined with a fixed concentration of boric acid, influence nickel electrodeposition in an aqueous solution, with minimal effect on the speciation of Ni(II) clusters. NA inhibits the Ni(II) reduction process even at a low concentration of 0.01 M, resulting in negligible changes in behavior compared to the additive-free environment. A higher concentration of 0.06 M NA is required to achieve a high-quality surface. The study demonstrates that the inclusion of NA significantly alters the electrochemical behavior relative to the additive-free regime. For instance, the use of both additive systems leads to coatings with relatively high microhardness and brighter, smoother deposits.

Recovery of indium by solvent extraction with crown ether in the presence of KCl and stripping with HCl: A mechanistic study

Hydration of In3+ is the main factor limiting its extraction efficiency from an aqueous solution during a liquid-liquid extraction process. In this study, KCl was introduced into the aqueous solution to facilitate the formation of InCl4− of low charge density, which is expected to possess much weaker hydration compared with In3+, promoting the solvent extraction of indium. The crown ethers (CEs) with varied cavity sizes, benzo-18-crown-6 (B18C6), benzo-15-crown-5 (B15C5), and benzo-12-crown-4 (B12C4), were synthesized. The extraction performance of the CEs toward indium in the presence of sufficient KCl in the aqueous solution was investigated. The liquid-liquid extraction process was analyzed theoretically based on density functional theory (DFT) from the aspects of thermodynamics, geometric structure optimization, electrostatic potential (ESP), and independent gradient model (IGM). The theoretical evaluations agreed well with the experimental results that the hydration of indium could be significantly weakened through the formation of InCl4− and the complexation ability of the CEs toward indium is in the order of B18C6 > B15C5 > B12C4. The complexation mechanism between the CEs and indium during the extraction process was further explored with the assistance of 1H NMR spectrum and SEM-EDS. The results indicate that crown ether coordinates with K+ to form [CE-K]+ at the two-phase interface, which further associates with InCl4− to create the complex of CE-KInCl4, realizing the efficient indium extraction. Moreover, B18C6 showed excellent selectivity toward In3+ over the competing ions such as Fe3+, Al3+, Zn2+, Sn2+ and Ca2+ in a complex system. Indium could be efficiently recovered from the loaded organic phase by using 1 M HCl as the stripping agent with a stripping efficiency of 98.1%.

Adsorptive removal of phosphate from water with biochar from acacia tree modified with iron and magnesium oxides

A novel biochar (BC) from Acaciatortilis trees pruning waste was synthesized and tested for the removal of phosphate from aqueous solutions. The BC was prepared by calcination at 600 °C and doped with Fe3O4 and MgO by hydrothermal process. The presence of iron and magnesium ions in the modified BC was confirmed by EDS analysis and X-ray diffraction (XRD) methods. Both unmodified and doped BCs were tested for phosphate removal from synthetic 1–500 ppm aqueous solutions. While the unmodified BC did not show any significant removal of phosphate from aqueous solutions, the modified BC almost completely removed phosphate from water. The enhancement in removal efficiency is due to an increase in the overall surface charge and surface area of BC as a result of doping with Fe3O4 and MgO salts. The average porosity and BET surface area corresponding to the plain BC increased by more than 20% from 322 to 394 m2/g after modification by impregnation with iron oxide and magnesium oxide. The modificaiton of BC with Fe3O4 and MgO nanoparticles was observed to increase the point of zero electric charge (PZC) from pH 3.4 (corresponding to plain BC) to pH 5.3 (corresponding to modified BC). The adsorption process was very fast and a phosphate removal value of 82.5% was reached only after 30 min of adsorption, while the removal efficiency after 4 h of adsorption was 97.5%. The rapid removal efficiency in short contact time is attributed to the high surface area of BC and strong bonding between the modified BC surface and PO43− ions. The highest adsorption capacity was observed to correspond to 98.5 mg/g which was achieved at PO43− concentration of 500 ppm and pH 8.5. Moreover, after fitting the adsorption data onto four of the most widely used adsorption isotherm models, the adsorption of PO43− onto BC can be better described by the Langmuir isotherm model.

Highly sensitive Raman measurements of protein aqueous solutions using liquid-liquid phase separation.

A highly sensitive method is proposed for obtaining the Raman spectra of low-concentration proteins and nucleic acids in an aqueous solution using liquid-liquid phase separation. This method uses water droplets formed by adding a large amount of polyethylene glycol into a biomolecular aqueous solution. Ordinary spontaneous Raman spectra are obtained with a high signal-to-noise ratio.

Synergy of {Co(H2O)6}2+ with a Polyoxometalate Leads to Aqueous Homogeneous Hydrogen Evolution: Experiments and Computations.

In this work, we have described a polyoxometalate (POM)-based inexpensive and easily synthesizable compound [Co(H2O)6]2[{K(H2O)}2V10O28]·2H2O (1), which exhibits electrocatalytic hydrogen evolution in its aqueous solution without its decomposition (or electrodeposition), acting as a rare homogeneous electrocatalyst. Even though the compound [Co(H2O)6]2[{K(H2O)}2V10O28]·2H2O (1) (soluble in water) shows electrocatalytic hydrogen evolution reaction (HER) activity because of the Coulombic attraction, including H-bonding interactions, between the [Co(H2O)6]2+ cationic species and [{K(H2O)}2V10O28]4-anionic species, the individual homogeneous solutions of [V10O28]6- (source: Na6[V10O28]·18H2O) and [Co(H2O)6]2+ (source: CoCl2·6H2O) do not show any electrocatalytic HER activity. We have thus established that the synergy of [V10O28]6- with [Co(H2O)6]2+ in crystal matrix as well as in the aqueous solution of 1 makes the compound 1 a stable and highly active electrocatalyst for homogeneous HER in an aqueous solution. In order to corroborate these homogeneous HER studies, we performed density functional theory (DFT) calculations to show that decavanadate cluster anion [V10O28]6- interacts with hexa-aqua complex cation [Co(H2O)6]2+ via strong H-bonding interactions, leading to a synergy effect that enables the cobalt center of [Co(H2O)6]2+ to be an active site of HER in the present work.

Near-infrared and multifunctional fluorescent probe enabled by cyanopyridine cyanine dye for bisulfite recognition and biological imaging

SO2 derivatives, sulfite/bisulfite, are widely employed in both the food processing and drug synthesis industries. Despite their widespread application, excessive levels of sulfite/bisulfite can negatively impact human health. Most probes for detecting sulfite/bisulfite are restricted by their fluorescence within the visible spectrum range and poor solubility in aqueous solution, which limit their use in food testing and biological imaging. Herein, a near-infrared probe comprising of the cyanopyridine cyanine skeleton, 4-((Z)−2-((E)−2-chloro-3-(2-cyano-2-(1-methylpyridine-4(1H)-ylidene)ethylidene)cyclohex-1-en-1-yl)−1-cyanovinyl)−1-methylpyridin-1-ium (abbreviated as CCP), was developed. This probe enables precise quantification of bisulfite (HSO3-) in almost pure buffered solutions, showing a near-infrared fluorescence emission at 784 nm with an impressively low detection limit of 0.32 μM. The probe stands out for its exceptional selectivity, minimal susceptibility to interference, and strong adaptability. The probe CCP utilizes the CC bond to trigger a near-infrared fluorescence quenching reaction with HSO3- via nucleophilic addition, which effectively disrupts the large delocalization within the molecule for accurate HSO3- identification. Moreover, the probe has been successfully applied in detecting HSO3- in various food products and living cells, simplifying the measurement of HSO3- content in water samples. This advancement not only enhances the analytical capabilities but also contributes to ensuring food safety and environmental protection. Environmental ImplicationSO2 derivatives including sulfite/bisulfite, serving dual roles as preservatives and antioxidants, have widespread application across various sectors including food preservation, water sanitation, and the pharmaceutical industry. Despite their widespread application, excessive levels of sulfite/bisulfite can affect human health. Developing methods for precisely and sensitively detecting sulfite/bisulfite in food products and biological samples is important for ensuring food safety and environmental protection. Here, a sensitive near-infrared and multifunctional fluorescent probe in a 99.9 % buffered solution, along with water gel encapsulation, has been successfully applied for the detection of bisulfite in food, authentic water samples, and biological cells.

Hybrid chitosan/HKUST-1 hydrogel with freezing and thawing modification as sustainable porous material for removal and selective separation of dye mixtures

A hybrid chitosan monolithic hydrogel (CS) was modified by incorporating with HKUST-1 and fabricated using an in-situ growth method. The resulting hydrogel CS/HKUST-1 was further modified to enhance the porous structure, in which the porous converted from close pores to interconnected porous structures. The chemical and physical characteristics of the modified hydrogel were examined using various characterization techniques like BET, SEM, EDX, FTIR, XRD, Zeta potential, and compression test to understand the effect of the modification. The outcomes displayed that this method provided homogeneous dispersing of HKUST-1 crystals within the chitosan hydrogel matrix, which can improve the material's specific surface area and adsorption capacity. The CS/HKUST-1 monolithic hybrid hydrogel's permeability is further enhanced by the freezing and thawing process and the produced hydrogel is called FCS/HKUST-1, which helps to open the hydrogel's pores and significantly increases its surface area. FCS/HKUST-1 hydrogels display higher mechanical properties without fracture after compression with elastic properties, whereas the CS/HKUST-1 hydrogel crashed at around 47 % compression strain. Consequently, the obtaining dual modified chitosan/ HKUST-1 hydrogel (FCS/HKUST-1) was evaluated as an adsorbent to eliminate Eosin Y (EY) dye from its aqueous solution and the adsorption mechanism was proposed as multilayer adsorption depending on the Freundlich isotherm model. The modified monolithic hydrogel displayed an excellent maximum adsorption capacity with EY dye about 625 mg·g−1. The FCS/HKUST-1 hydrogel showed extremely selective removal for anionic dye higher than cationic dye, which allows facile separation of the dyes with different charges in a mixture solution. The outcomes also demonstrate that the modified hydrogel would be an eco-friendly material, which shows excellent recyclability, indicating that this material considerable promising adsorbent in water treatment.

Enhanced photocatalytic performance of rGO/UiO-66(Zr)/Ag3PO4 composite for degradation of methyl orange (MO) under visible light irradiation

Industries like textile, plastic, pulp, and paper produce dye-containing waste waters that have harmful effect on the environment as well as human health. This work presents a series of binary and ternary composites formed by reduced graphene oxide (rGO), silver phosphate (Ag3PO4) and the nanocrystalline MOF, UiO-66(Zr). The composites exhibit the best of their catalytic features to achieve efficient photocatalysis to remove the model dye methyl orange (MO) from aqueous solution as well as dyes from a real industrial wastewater effluent. The composites were prepared under sustainable conditions, at room temperature. XRD characterization shows that the prepared MOF is one of the most nanocrystalline reported UiO-66(Zr), becoming even more nanocrystalline in the composite formation. Different physicochemical characterization techniques indicated the existence of such interaction. Thus, DRS-UV-vis spectroscopy makes clear the reduction of the band-gap of the composites compared with the individual components; the band intensity of the photoluminescence (PL) spectra is substantially reduced in composites, confirming the diminution of electron-hole recombination; and electrochemical impedance spectroscopy (EIS) shows that the electrodes modified with ternary composites present faster electron transfer ability. The selected composite rGO/UiO-66(Zr)/Ag3PO4 exhibits high efficiency on the photodegradation of the model MO dye compared to the binary and single counterparts. It could be attributed to its high surface area, enhanced visible light absorption, efficient charge transfer process, as well as the synergetic effect between its components. A degradation mechanism is proposed based on the estimated band-gaps and on the scavenging study with strategically-chosen species.

Energy Transfer Processes in NaBiF4 Nanocrystals Co‐Doped with Tb3+ and Eu3+ Dispersed in Aqueous Solution

AbstractThe synthesis of hexagonal NaBiF4 co‐doped with Tb3+ and Eu3+(NaBi0.75−xTb0.25EuxF4; with x=0, 5, 10, 20 and 30) was achieved via a facile and fast precipitation route at 35 °C. Powder X‐ray diffraction (PXRD) and luminescence spectroscopy have been employed to characterize and investigate the materials. The study of luminescence spectroscopy and decay kinetics of the 5D4 excited state of Tb3+ provides the evidence of a Tb3+→Eu3+ energy transfer process. Sodium citrate has been adopted as capping agent to promote a homogeneous dispersion of the materials into water and to protect the inorganic host, which is water sensitive, from direct contact with this molecule. The comparison of luminescence properties between bare and citrate‐capped samples of NaBiF4 co‐doped with Tb3+ and Eu3+ reveals a marked difference in the Tb3+→Eu3+ energy transfer efficiency, which has been tentatively explained on the basis of a different environment surrounding the lanthanide ions in the two families of compounds.

Efficient removal of emerging pollutant oxytetracycline by cost‐effective biochar–hydroxyapatite composite

AbstractBiochar (BC) and hydroxyapatite (HAp) are widely used in environmental remediation due to their high adsorption capacity, porous structure, large specific surface area, chemical stability, non‐toxicity, and low solubility. Combining BC and HAp is a green and effective strategy for creating new adsorbents (BCH) that have a synergistic impact on wastewater treatment. In this study, BCH composites derived from apatite ore and macadamia nut shells were synthesized by the wet impregnation method to remove oxytetracycline (OTC) from aqueous solutions. The BC‐HAp composite with a ratio of 10:1 (by weight) was the most effective material for removing OTC. The Redlich–Peterson model achieved the highest correlation coefficient among the four models tested (Freundlich, Langmuir, Temkin, and Redlich–Peterson). The maximum adsorption capacity calculated with the Langmuir isotherm was 49.59 mg g−1. It was found that the adsorption process was significantly affected by the solution pH. The bipolar form of the drug was found to be OTC±, and the adsorption was most effective in solutions with a pH of 6. The OTC adsorption dominant mechanisms on nanocomposites could be electrostatic attraction, hydrogen bonding formation, surface complexation, or ion exchange. Therefore, the BCH composite showed great potential for removing OTC pollutants in a cost‐effective, and environmentally friendly manner.

Supreme capture of Europium(ΙΙΙ) by silica-hyperbranched poly(ethylene imine) composites from aqueous solutions − A mechanistic study

Two bio-inspired variations of the sol–gel technique produced silica-hyperbranched poly (ethylene imine) (PEI) composite nanoparticles (NP) and xerogels (XG). Both methods are performed in ambient conditions and do not require toxic organic solvents or high temperatures. We have investigated the removal efficiency of trivalent europium by these two hybrid species in near-neutral aqueous solutions. The adsorption kinetics and isotherms, including data fitting with the pseudo-first and second order kinetic, and the Langmuir isotherm model are presented and discussed. Thermodynamic parameters indicate exothermic reaction (–180 kJ/mol for NP and –192 kJ/mol for XG, respectively) In addition, spectroscopic (Fourier Transform Infra-Red FTIR, Fluorescence Spectroscopy FS, X-ray Photoelectron Spectroscopy XPS) and microscopic techniques (Scanning Electron Microscopy SEM coupled with Energy Dispersive X-ray analysis EDX), as well as ζ-potential and Dynamic light scattering (DLS) measurements, have been employed to evaluate the interaction mechanism between the surface active moieties and Eu(III). The extremely high and homogeneous dispersion of the amino and silicate groups of the composites has led to the highest capacity value (22 mmol/g or 3343 mg/g and 14 mol/g or 2128 mg/g for the two distinct forms of the nanoparticles and the xerogels, respectively) reported up to today implying a potential application for lanthanide recovery. The adsorption data along with the spectroscopic and microscopic indicate that the adsorption is well described by the Langmuir isotherm model and is based on the formation of inner- and outer-sphere complexes between Eu(III) the amine and −Si-O− moieties.

Crystal Structure of the Native Chromoprotein from Pleurotus salmoneostramineus Provides Insights into the Pigmentation Mechanism.

The pink-colored protein from the fungus Pleurotus salmoneostramineus (PsPCP) possesses unusual primary sequences with little resemblance to those of known proteins and exhibits a red color in aqueous solution. To understand the pigmentation mechanism of PsPCP, we elucidated the X-ray crystal structure of the native PsPCP. We identified a highly conjugated polyene ligand 2-dehydro-3-deoxylaetiporic acid A as a chromophore ligand, whose solution exhibits yellow. The crystal structure of PsPCP indicated that the ligand is secured in the central cavity and anchored at both termini by hydrophilic interactions and that surrounding residues show CH-pi and C-H···O hydrogen bondings. Geometrical analyses of the bound ligand demonstrated that the conjugated C-C and C═C bonds exhibit similar bond distances. The result indicated enhanced electron delocalization within the conjugated CC bond system, resulting in a redshift of the chromophore ligand. The computational estimates of the UV-vis spectra support the view that the electron delocalization within the conjugated CC bonds system of the bound ligand, induced by the specific ligand geometry within a limited space of PsPCP cavity, is responsible for the red pigmentation of PsPCP. Thus, we propose that the coloring mechanism of PsPCP, which constrains the geometry of a highly conjugated polyene ligand, is a novel type of pigment chemistry.

Synthesis of locust bean gum/titanium dioxide hydrogel nanocomposites for efficient removal of methylene blue from aqueous solution

Synthesis of locust bean gum/titanium dioxide hydrogel nanocomposites for efficient removal of methylene blue from aqueous solution

Strategy to Simultaneously Manipulate Direct Zn Nucleation and Hydrogen Evolution via Surface Modifier Hydrolysis for High-Performance Zn-Ion Batteries.

The demand for safer batteries is growing rapidly due to fire incidents in electronic devices that use Li-ion batteries. Zn-ion batteries are among the most promising candidates to replace Li-ion batteries because they use a water-based electrolyte and are not explosive. However, Zn-ion batteries suffer from persistent corrosion and dendritic crystal formation during the charge-discharge process, which decrease their reversibility and hinder their commercial usage. Extensive research has been conducted to address these issues, but there are significant limitations due to high process and time costs. In this study, the modulation of the Zn-electrolyte interface to overcome these challenges is attempted using acetamide-derived thioacetamide (TAA), a surface modifier used in electroplating. TAA undergoes hydrolysis in an aqueous solution and produces weakly acidic byproducts and sulfide ions. These species are adsorbed onto the Zn metal surface, which induces uniform Zn2+ deposition, facilitates the formation of a stable interfacial layer, and inhibits side reactions due to the reduced water activity. Consequently, the symmetric cell with TAA achieves a low polarization of 50 mV and stable cycling for 700 h at 1 mA cm-2. Additionally, a Zn|V6O13 full cell exhibits electrochemical reversibility, maintaining a capacity retention of 64% over 300 cycles. Therefore, this study offers useful insights into the development of a simple manufacturing process to ensure the competitiveness of Zn-ion batteries for practical applications using functional electrolyte additives.

Theranostic dye entrapped in an optimized blended-polymer matrix for effective photodynamic inactivation of diseased cells.

Despite the wide range of treatment options available for cancer therapy, including chemotherapy, radiation therapy, and surgical procedures, each of these treatments has a different side-effect profile and leaves the patient with no option but to choose. Due to their insensitivity and nonspecificity, conventional treatments damage normal cells together with cancer cells. In recent years, a significant amount of attention has been focused on photodynamic therapy (PDT) as a treatment for cancer and drug-resistant microbes. An activated photosensitizer is used as a part of the procedure along with oxygen molecules and a specific wavelength of light belonging to the visible or NIR spectral zone. A light-sensitive laser dye, rhodamine 6G (R6G), was used in the present study as a photosensitizer, taking a challenge to improve the aqueous solubility and ROS quantum yield using optimum concentration (160mg/ml) of chitosan-alginate (Cs-Alg) blended polymeric nanoformulations. As evidenced by steady-state spectrophotometric and fluorometric measurements, ROS quantum yield increases three-fold over aqueous solution along with solubility gaining that was validated by PDT experiment using human epithelial carcinoma (KB) cell line. Phantom optical imaging was taken using the IVIS imaging system to establish the formulations as a fluorescence-based optical contrast agent, and zebrafish embryos were used to establish their safe in vivo use. The release profile of R6G was fitted using kinetic models, which followed the Non-Fickian kinetic profile. In conclusion, we recommend the formulations as a potential theranostic agent that will aid in PDT-based therapy in conjunction with optical imaging-based diagnosis.

Exploring Mucoadhesive and Toxicological Characteristics Following Modification of Linear Polyethylenimine with Various Anhydrides.

Linear polyethylenimine (L-PEI) has numerous applications, such as in pharmaceutical formulations, gene delivery, and water treatment. However, due to the presence of secondary amine groups, L-PEI shows a relatively high toxicity and low biocompatibility. Here, various organic anhydrides were used to modify L-PEI to reduce its toxicity and enhance its functionality. We selected methacrylic anhydride, crotonic anhydride, maleic anhydride, and succinic anhydride to modify L-PEI. The structure of the resulting derivatives was characterized using 1H NMR and FTIR spectroscopies, and their behavior in aqueous solutions was studied using turbidimetric and electrophoretic mobility measurements over a broad range of pHs. A fluorescence flow through method determined the mucoadhesive properties of the polymers to the bovine palpebral conjunctiva. Methacrylated L-PEI and crotonylated L-PEI showed strong mucoadhesive properties at pH 7.4, likely due to covalent bonding with mucin thiol groups. In contrast, maleylated and succinylated L-PEI were poorly mucoadhesive as the pH was above their isoelectric point, resulting in electrostatic repulsion between the polymers and mucin. The toxicity of these polymers was evaluated using in vivo assays with planaria and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) cell viability assay in human alveolar epithelial cells. Moreover, the irritancy of polymers was assessed using a slug mucosa irritation assay. The results demonstrated that anhydride modification mitigated the adverse toxicity effects seen for parent L-PEI.

Reflection coefficient of a natural sodium bentonite in aqueous mixed electrolyte solutions: positive and negative anomalous osmosis

Reflection coefficient of a natural sodium bentonite in aqueous mixed electrolyte solutions: positive and negative anomalous osmosis

The “Pull Effect” of a Hanging ZnII on Improving the Four‐Electron Oxygen Reduction Selectivity with Co Porphyrin

AbstractDue to the challenge of cleaving O−O bonds at single Co sites, mononuclear Co complexes typically show poor selectivity for the four‐electron (4e−) oxygen reduction reaction (ORR). Herein, we report on selective 4e− ORR catalyzed by a Co porphyrin with a hanged ZnII ion. Inspired by Cu/Zn‐superoxide dismutase, we designed and synthesized 1‐CoZn with a hanging ZnII at the second sphere of a Co porphyrin. Complex 1‐CoZn is much more effective than its Zn‐lacking analogues to catalyze the 4e− ORR in neutral aqueous solutions, giving an electron number of 3.91 per O2 reduction. With spectroscopic studies, the hanging ZnII was demonstrated to be able to facilitate the electron transfer from CoII to O2, through an electronic “pull effect”, to give CoIII‐superoxo. Theoretical studies further suggested that this “pull effect” plays crucial roles in assisting O−O bond cleavage. This work is significant to present a new strategy of hanging a ZnII to improve O2 activation and O−O bond cleavage.

Standardized Electric-Field-Resolved Molecular Fingerprinting.

Field-resolved infrared spectroscopy (FRS) of impulsively excited molecular vibrations can surpass the sensitivity of conventional time-integrating spectroscopies, owing to a temporal separation of the molecular signal from the noisy excitation. However, the resonant response carrying the molecular signal of interest depends on both the amplitude and phase of the excitation, which can vary over time and across different instruments. To date, this has compromised the accuracy with which FRS measurements could be compared, which is a crucial factor for practical applications. Here, we utilize a data processing procedure that overcomes this shortcoming while preserving the sensitivity of FRS. We validate the approach for aqueous solutions of molecules. The employed approach is compatible with established processing and evaluation methods for the analysis of infrared spectra and can be applied to existing spectra from databases, facilitating the spread of FRS to new molecular analytical applications.