Fourier Transform Infrared Spectroscopy Characterization Research Articles

Efficient removal of chlortetracycline hydrochloride and doxycycline hydrochloride from aqueous solution by ZIF-67

ZIF-67 nanoparticles were synthesized by a simple method at room temperature and used to remove chlortetracycline hydrochloride (CTC) and doxycycline hydrochloride (DOX) from water. ZIF-67 was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) surface area, X-ray photoelectron spectroscopy (XPS), thermogravimetry (TGA) and zeta potential analyzer. The morphology and chemical composition of the synthesized ZIF-67 were characterized. The effects of key parameters such as pH, dosage, temperature, contact time, different initial concentrations and coexisting ions on the adsorption behavior were systematically studied. The results of batch adsorption experiments indicate that the adsorption process conforms to the pseudo-second-order kinetic model and Sips model. At 303K, the removal rates of CTC and DOX at 150 mg/L reached 99.16 % and 97.61 %, and the maximum adsorption capacity of CTC and DOX reached 1411.68 and 1073.28 mg/g, respectively. At the same time, ZIF-67 has excellent stability and reusability. Most importantly, the possible adsorption mechanism is proposed by exploring the changes of SEM, TEM, BET and FT-IR characterization results before and after the reaction, which mainly includes pore filling, electrostatic interaction and π-π interaction. The prepared ZIF-67 has a large specific surface area (1495.967 m2 g−1), achieves a high removal rate within a short time frame, and maintains a high removal rate across a wide pH range. These characteristics make ZIF-67 a potentially promising adsorbent for removing antibiotics from aqueous solutions.

FTIR Characterization of Bioactive Functional Groups Present in Crude Extract of Mycoherbicides Produced from Consortium Culture of Rhizosphere Fungal Isolates

ABSTRACT Consortium culture can be a relatively cheap and environment-friendly technology for producing secondary metabolites like pesticides (herbicides). This study produced some metabolites from a consortium culture of fungal isolates obtained from the rhizospheres of Panicum maximum, Ipomoea involucrata and Amaranthus viridis. The isolates from rhizospheres of the above-named plants were co-cultured using Czapek broth and were incubated in an incubator shaker for 28 days. The co-culture combinations were: Aspergillus welwitschiae and Trichoderma hamatum (consortium 1), Aspergillus welwitschiae and Aspergillus aculeatus (consortium 2), and Aspergillus aculeatus and Trichoderma hamatum (consortium 3). Crude extracts from each consortium were characterized using Fourier Transform Infrared Spectroscopy (FTIR). The FTIR results showed that consortium 1 had peak spectra range from 418.57 cm−1 (S–S stretch of aryl disulfides) to 3462.34 cm−1 (alcohol, aliphatic primary amine), consortium 2 had peak spectra range from 420.5 cm−1 (halo compound) to 3456.65 cm−1 (alcohol, aliphatic primary amine) and consortium 3 had peak spectra from 457.14 cm−1 (halo compound) to 3448.84 cm−1 (alcohol, aliphatic primary amine). Some of the compounds produced by the consortia were pesticidal in nature and are hence, considered a potential technology in developing organic pesticides.

FT-IR Characterization and Phylogenetic Analysis of Patchouli Oil from West Aceh and Aceh Jaya using PCA and HCA

This study aims to characterize and compare the chemical composition of patchouli oil from various regions in Aceh, Indonesia, using Fourier-transform Infrared Spectroscopy (FT-IR) combined with Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA). Patchouli oil samples from five distinct locations within West Aceh and Aceh Jaya Regencies were analyzed, focusing on the 1800-500 cm⁻¹ range. The FT-IR spectra revealed significant chemical markers, with notable absorption bands corresponding to aliphatic C-H, C=O, and C=C stretching vibrations. Multivariate analyses showed distinct clustering patterns, with four samples (POSM, POSP, POT, and POW) exhibiting high chemical similarity and clustering together, while one sample (POP) formed a separate cluster, indicating a lower degree of similarity. PCA analysis of the original spectra in the 1800-500 cm⁻¹ range yielded a cumulative PC1 and PC2 value of 89%. The HCA dendrogram highlighted a significant relative distance of 10 between the POP sample and the other four samples, indicating minimal relatedness, with the closest relatedness observed between POSM and POSP, having a relative distance of 1.1. This study demonstrates the effectiveness of FT-IR spectroscopy combined with PCA and HCA in distinguishing chemical profiles of patchouli oil from different regions, providing insights into geographical and varietal influences on oil composition. The findings are crucial for quality control and standardization in the patchouli oil industry, with further molecular studies recommended to corroborate and enhance understanding of genetic diversity among patchouli varieties in Aceh.

Green Synthesis of Silver Nanoparticles with Snake Fruit Peel Extract: A Preliminary Study For Optimization of The Preparation Technique

In Indonesia, the pulp of snake fruit is consumed while the peel remains unused. In this context, the phytochemical content of snake fruit aqueous extract was used as a reducing and capping agent in the preparation of silver nanoparticles (AgNPs). According to the phytochemical screening, snake fruit peel containing alkaloids, flavonoids, tannins, saponins, and polyphenols was used to synthesize AgNPs. Therefore, this research aimed to optimize the synthesis of AgNPs using snake fruit peel extract (Salacca zalacca) in terms of synthesis time, temperature and phytochemical screening. AgNPs were successfully synthesized using a volume ratio of 2:15 (20 mL of 1.00 mM AgNO3 to 150 mL of snake fruit peel extract) in a sealed container in a dark room. Furthermore, characterization was carried out using a UV-Vis spectrum and Fourier Transform Infrared Spectroscopy (FTIR). The UV-Vis spectrum characterization in a solution incubated for 30 minutes at 30 °C with a concentration of 1.00 mM AgNO3 was differentiated at a wavelength of 410 nm with an absorbance of 2.361. According to the FTIR characterization, there was an increase in the intensity of the O – H functional groups in the AgNPs solution compared to snake fruit peel extract. The results showed that the synthesis of AgNPs from snake fruit peel extract was optimal at a concentration of 1.00 mM AgNO3 at 30 °C and 30 minutes of incubation.

Effect of surfactants (cetyl trimethyl ammonium-bromide, ethyl di-tetra amine and polyacrylamide) on the synthesis of zinc oxide for photocatalytic application

In this work, we report the effect of cetyl trimethyl ammonium bromide (CTAB), ethyl di-tetra amine (EDTA) and polyacrylamide as surfactants on synthesis of zinc oxide for photocatalytic application. The ZnO nanoparticles were synthesized with and without the surfactants and characterized using powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). In addition to this, the morphology of zinc oxide prepared in the absence and presence of these surfactants investigated through scanning electron microscopy (SEM). As confirmed from XRD and FTIR characterization results, the use of different surfactants did not affect the composition of ZnO nanomaterials. The photocatalytic activities were investigated by the degradation of methylene blue (MB) dye under sunlight irradiation. To optimize the effects of operational parameters, the study was carried out as a function of dye concentration, catalyst dose, and pH on the degradation efficiency of the photocatalysts. The optimum values of catalyst dose, dye concentration and pH of solution were found to be 0.09 g, 5 mg/L and 10, respectively. The ZnO nanomaterials prepared with CTAB surfactant showed highest degradation efficiency of 98% indicating potential application for practical decontamination of wastewater from toxic organic pollutants. KEY WORDS: Surfactants, Zinc oxide nanoparticles, Photocatalysis, Methylene blue Bull. Chem. Soc. Ethiop. 2024, 38(4), 923-935. DOI: https://dx.doi.org/10.4314/bcse.v38i4.9

Exploring the effect of polyacrylamide/graphene oxide composite hydrogel on the synthesis and application of ZSM-5 molecular sieves

Herein, we demonstrate the synthesis of coffin-shaped ZSM-5 molecular sieves in polyacrylamide (PAM)/graphene oxide (GO) composite hydrogel using the hydrothermal method. The as-synthesized products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS), and Thermogravimetry analyses (TGA). The effect of PAM and GO addition on the morphology and structure of ZSM-5 was investigated. The results indicated that the introduction of PAM and GO promoted the growth of the ZSM-5 (101) plane. Moreover, samples synthesized in the PAM/GO hydrogel exhibited a longer c-axis and a more pronounced coffin-shaped morphology compared to samples synthesized solely in PAM hydrogel. The Si/Al ratio decreased with the addition of GO, possibly due to interface effects leading to the formation of ZSM-5 precursors with a higher Al content. TG, FT-IR, and XPS characterization revealed hydrogen bonding interactions between PAM and GO, and the addition of GO likely restricted the movement of polymers, improving cross-linking between monomers and forming a more uniform network structure. The sample G-15 (P-5) exhibited higher mesopore volume and average pore diameter, contributing to enhanced catalytic performance. However, with increasing GO content, the average pore diameter decreased, potentially due to functional groups on the surfaces of graphene oxide and polyacrylamide forming a more uniform and structurally stable three-dimensional network structure. This allowed for controlled modulation of the molecular sieve morphology and pore size. The introduction of PAM/GO hydrogel resulted in a moderate amount of weak acid and an increased amount of strong acid, both shifting to lower temperatures. The ZSM-5 molecular sieves synthesized in the PAM/GO composite hydrogel demonstrated outstanding MTO catalytic performance, exhibiting high selectivity for light olefins and an extended catalytic lifespan. This work is expected to provide new ideas and methods for developing efficient ZSM-5 catalysts.

Methods Development and Validation for the Estimation of Pioglitazone HCl in Bulk and Formulations by UV Spectroscopy and FTIR

The use of spectroscopic analysis, particularly UV spectrophotometer, is a simple and essential technique for bulk drug estimation, formulation studies, and compatibility assessments of drugs with various excipients. In the pharmaceutical industry, various analytical instruments, including Fourier transform infrared spectroscopy (FTIR), are employed for investigating drug-excipient interactions that can impact the stability of active pharmaceutical ingredients. This study aimed to develop a UV spectrophotometric method for the analysis of Pioglitazone hydrochloride in phosphate buffer (pH 7.4) and methanolic solution, assessing its linearity and compliance with Beer's Law. Furthermore, we aimed to use FTIR to characterize potential interactions between Pioglitazone and common pharmaceutical excipients, such as Guar Gum, Chitosan, and Sodium Alginate. Standard solutions of Pioglitazone were prepared in phosphate buffer (pH 7.4) and methanol. UV spectrophotometer was conducted to determine the maximum absorption wavelength. Calibration curves were constructed to evaluate linearity and adherence to Beer's Law. FTIR analyses were performed to investigate drug-excipient interactions by examining the functional groups. In phosphate buffer (pH 7.4), the maximum absorption wavelength for Pioglitazone hydrochloride was 268 nm. The calibration curve for Pioglitazone in phosphate buffer (pH 7.4) demonstrated linearity in the concentration range of 1–20 µg/ml, with a correlation coefficient of 0.998. In methanol, the maximum absorption wavelength for Pioglitazone hydrochloride was found to be 272 nm. The calibration curve in methanol exhibited linearity in the range of 1–20 µg/ml, with a correlation coefficient of 0.999. FTIR analysis revealed potential drug-excipient interactions, particularly in the case of Guar Gum, Chitosan, and Sodium Alginate, suggesting the formation of stable hydrogen bonds. The developed UV spectrophotometric method for Pioglitazone analysis is a reliable, cost-effective, and reproducible approach, making it a valuable tool for drug development and quality control. Additionally, the FTIR characterization confirmed interactions between Pioglitazone and common pharmaceutical excipients, enhancing our understanding of formulation compatibility.

(Energy Technology Division Graduate Student Award sponsored by BioLogic) Probing and Engineering Electrode-Electrolyte Interfaces in Electrochemical Energy Storage and Conversion

Climate change demands the development of clean energy technologies, where rechargeable batteries and fuel cells promise a bright future by integrating with solar or wind energy. Li-ion batteries and fuel cells also play essential roles in electrifying transportation in replacement of internal combustion engines. Central to these electrochemical systems is the electrode-electrolyte interface, where (electro)chemical surface reactions or intercalation reactions occur, and its thermodynamic and kinetic properties determine the energy density, power density, and lifetime of the electrochemical devices. However, the molecular structures at the interface and how they promote or suppress the desired reactions remain unclear, hindering the rational design of electrode-electrolyte interfaces to improve the performance of electrochemical devices.This talk focuses on the fundamental understanding of the interfacial (electro)chemical reaction mechanisms at the molecular level and charges transfer kinetics at the electrified interfaces. First, an in situ Fourier-transform infrared spectroscopy (FTIR) method was developed to examine the parasitic reactions between carbonate electrolytes and lithium nickel, manganese and cobalt oxides (NMC) in Li-ion batteries, and unique evidence for dehydrogenation reactions on Ni-rich NMC was revealed, which accounted for interface impedance build-up and battery capacity fading. Based on the proposed mechanism, strategies based on electrolyte non-covalent interactions were demonstrated to improve battery lifetime. In the second part of the talk, the research extended in situ FTIR characterization and electrolyte engineering to electrocatalytic reactions central to fuel cell technologies. An interfacial layer of protic ionic liquids with different acid dissociation constants were found to enhance the oxygen-reduction reaction (ORR), attributed to strengthened hydrogen bonding between ORR products and ionic liquids, revealed by in situ surface-enhanced infrared absorption spectroscopy and density functional theory (DFT) calculations. For the hydrogen evolution reaction (HER), similarly, promoting hydrogen bonding between interfacial water molecules also facilitated proton-coupled electron transfer kinetics, resulting in favorable HER in controllable organic confinements. Finally, this talk will introduce fundamental, theoretical aspects of charge transfer processes at the electrode-electrolyte interface - the kinetic mechanism for ion intercalation. Experimental evidence from a charge-adjusted electrochemical method showed that Li-ion intercalation occurs by coupled ion-electron transfer (CIET), which governs the current-dependent maximum capacity and power density of intercalation batteries. these research efforts have laid a solid foundation for the rational design of electrochemical interfaces employing the physical chemistry of electrodes and electrolytes, for next-generation electrochemical storage devices with improved energy and power density and cycle life.

Experimental and theoretical studies on dissolution and regeneration of microcrystalline cellulose with dihydroxyl ionic liquids

Ionic liquids (ILs) have emerged as a promising class of green solvents suitable for cellulose dissolution. In this study, two dihydroxyl-functionalized ionic liquids, 1-methyl-3-(2,3-dihydroxypropyl)-imidazolium chloride ([DPmim]Cl) and 1-butyl-3-(2,3-dihydroxypropyl)-imidazolium chloride ([DPbim]Cl), were prepared for microcrystalline cellulose (MCC) dissolution. The physical properties of [DPmim]Cl and [DPbim]Cl, such as relative viscosity, density, electrical conductivity, and Kamlet-Taft parameters (β and π*), were evaluated. The dissolution and regeneration properties of MCC in [DPmim]Cl and [DPbim]Cl were investigated. The regenerated MCC was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). Density functional theory (DFT) simulations were used to investigate the interactions between ionic liquid and cellobiose. [DPmim]Cl and [DPbim]Cl, with higher β-values (0.975 and 1.098) respectively, exhibited stronger hydrogen bonding alkalinity. This increased alkalinity enhanced their ability to accept hydrogen bonds from cellulose, which in turn weakened the inter- and intra-molecular hydrogen bonds within cellulose. As a result, the dissolution of MCC was promoted. The dissolution of MCC in [DPmim]Cl was faster than [DPbim]Cl at same temperature. FTIR, TGA, and XRD characterizations showed that the hydrogen bonding network of microcrystalline cellulose was disrupted during ionic liquid dissolution. DFT simulations unveiled the formation of strong hydrogen bonds between the hydroxyl groups of ILs and the hydroxyl or ether linkages in cellulose. These hydrogen bonds have been identified as a potential crucial factor in facilitating the dissolution of cellulose.

Synthesis and characterization of silver nanoparticles using reducing agents of bitter leaf (Vernonia amygdalina) extract and tri-sodium citrate

The aim of this work was to synthesize silver nanoparticles (AgNPs) using trisodium citrate and extract obtained from Vernonia amygdalina plant leaves as a chemical and biological reducing agent, respectively, and to investigate the impact of different experimental conditions on the stability and particle size of the acquired nanoparticles. Particle size analyzers, UV–Vis​ spectrophotometry, Fourier-transform infrared spectroscopy (FTIR) analysis and X-ray diffraction (XRD) were used to characterize the synthesized AgNPs. During the reduction reaction, a notable change in the color of the colloidal solution from colorless to gray indicated that the Ag+ ion was reduced to Ag0. The maximum absorption in the UV–Vis spectra for the acquired AgNPs in aqueous solution had wavelengths of 452 and 437 nm, respectively, for the biological and chemical methods. The average particle sizes of the prepared AgNPs using the green and chemical reducing agents were found to be 63.08 and 38.47 nm, respectively. FTIR characterization on dry powders of the AgNP samples showed different features for the functional groups and phytochemicals. The XRD patterns have confirmed that the powder particles of the AgNPs are crystalline in nature, with the face centered cubic phase (FCC). It was found that the AgNPs that were prepared by the green method had more stability than those prepared by the chemical method. The green method is simple, affordable, eco-friendly and green compared to the chemical method.

Synchrotron-Based Fourier-Transform Infrared Micro-Spectroscopy of Cerebrospinal Fluid from Amyotrophic Lateral Sclerosis Patients Reveals a Unique Biomolecular Profile.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, with the most common adult-onset neurodegenerative disorder affecting motoneurons. Although disruptions in macromolecular conformation and homeostasis have been described in association with ALS, the underlying pathological mechanisms are still not completely understood, and unambiguous biomarkers are lacking. Fourier Transform Infrared Spectroscopy (FTIR) of cerebrospinal fluid (CSF) is appealing to extensive interest due to its potential to resolve biomolecular conformation and content, as this approach offers a non-invasive, label-free identification of specific biologically relevant molecules in a few microliters of CSF sample. Here, we analyzed the CSF of 33 ALS patients compared to 32 matched controls using FTIR spectroscopy and multivariate analysis and demonstrated major differences in the molecular contents. A significant change in the conformation and concentration of RNA is demonstrated. Moreover, significantly increased glutamate and carbohydrates are found in ALS. Moreover, key markers of lipid metabolism are strongly altered; specifically, we find a decrease in unsaturated lipids and an increase in peroxidation of lipids in ALS, whereas the total amount of lipids compared to proteins is reduced. Our study demonstrates that FTIR characterization of CSF could represent a powerful tool for ALS diagnosis and reveals central features of ALS pathophysiology.

Carotenoid from marine Bacillus infantis: production, extraction, partial characterization, and its biological activity.

Marine bacteria could serve as a potential source of natural carotenoids. Bacillus infantis, (Accession number OP601610), a bacterium with the ability to synthesize carotenoids, was isolated from the marine environment and used in this investigation to produce an orange pigment. Additionally, the production, extraction, partial characterization, and biological activity of orange pigment are reported in the current work. The orange pigment was identified as a carotenoid group of pigment by UV-Visible spectrophotometry, FTIR (Fourier-transform infrared spectroscopy), and TLC (Thin-layer chromatography) characterization of the methanolic extract of the pigment. The pigment showed antimicrobial activity against four Gram-negative strains (Pseudomonas aeruginosa, Shigella dysenteriae, Salmonella enterica ser. typhi MTCC 733, and Serratia marcescens MTCC 86), three Gram-positive strains (Bacillus megaterium MTCC 3353, Staphylococcus aureus MTCC 96, and Staphylococcus epidermis MTCC 3382), and antioxidant potential by ABTS [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)], DPPH (2,2-diphenyl 1-picrylhydrazyl), H2O2 (hydrogen peroxide), FRAP (Ferric reducing antioxidant power), and phospho-molybdate methods. These findings demonstrate that the carotenoids of the strains under research provide intriguing possibilities for biotechnological applications.

Adsorption of Carotene from Crude Palm Oil by Activated Achalla Clay

High costs of imported bleaching earths have led to the need for alternative local sources. The effectiveness of acid-activated Achalla clay in crude palm oil bleaching was examined. The clay sample was collected, sun-dried, manually ground, and activated with the hydrochloric acid solution. Characterization of the raw and activated clay samples was carried out using X-ray fluorescence (XRF), Scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) analyses. The factors that were varied during the bleaching process were temperature, contact time, and adsorbent dosage. The adsorption kinetics, adsorption isotherm, and thermodynamics studies were also investigated. The XRF, SEM, and FTIR characterization results showed that the clays were kaolinites with some significant increase in the number of microporous surfaces and some changes in the functional groups. The results also indicated that the process performance improved at higher temperatures. The highest bleaching efficiency of the bleaching process was 85.6%. The pseudo-first-order model described the adsorption process from the experimental data with higher correlation coefficients than the pseudo-second-order, first-order, and Intra-particle diffusion models. The equilibrium isotherm data were described better by the Temkin model than Langmuir and Freundlich models due to higher R2 values. The enthalpy and entropy values were determined to be 26,968.12 J/mol and 78.2273 J/mol respectively. The Gibb’s free energy was found to vary between -1.428.39 to 1,700.70 J/mol. The results of the thermodynamic parameters showed that it was a spontaneous chemical adsorption process and endothermic. This study has revealed that acid-activated Achalla clay can be used for the bleaching of crude palm oil at higher temperatures.

A comprehensive methodology for analysis of coagulation performance: Dosing approach, isotherm modelling, FTIR spectroscopy and floc characterization

Isolated studies for the evaluation of coagulation considering either microscopic or macroscopic dimensions have largely been discussed. However, comprehensive analysis of coagulation including various dimensions is imperative to design an optimal coagulation system. In this work, a comprehensive methodology has been described which includes dosing approach, mathematical modelling, chemical analysis by FTIR (Fourier Transform Infrared) spectroscopy, image analysis for floc properties and various analytical procedures. Jar tests were performed on simulated waters containing humic acid and kaolin using high basicity PACl (Poly Aluminium Chloride). A PODR (point of diminishing return) approach is used for the determination of coagulant dose corresponding to TOC (Total Organic Carbon), DOC (Dissolved Organic Carbon) and UV254 (Ultraviolet Absorbance at 254 nm). On average, PODR for UV254 was slightly greater than that of TOC followed by that of DOC. The correlation between the input TOC and PODR values was in the order: TOC (R2 = 0.84) > UV254 (R2 = 0.83) > DOC (R2 = 0.65). The isotherms are analyzed by non-linear error functions: RMSE (Root mean square error), HYBRID (Hybrid fractional error function), ARE (Average relative error), MPSD (Marquardt's percent standard deviation) and Chi-Square. It was observed that error functions RMSE, HYBRID and Chi-Square can be successfully used for non-linear analysis. However, ARE and MPSD cannot be used at low concentrations as they showed high residual values. Further, image processing is used to analyze floc size and fractal dimension. The interactions of species and the physical structure of flocs derived based on adsorption isotherms are corroborated by using the FTIR data.

Bionic artificial penile Tunica albuginea

Bionic artificial penile Tunica albuginea

FTIR Characterization and Physico-chemical Studies of Honey Samples in Kanpur Nagar

Honey is a valuable food entity that gains a lot of attention due to its potential benefits for health and its uses to sweeten foods. It contains about 60% invert sugar and appreciable amounts of maltose and sucrose. In this study, the Physico-chemical characteristics of pure and adulterated honey samples were investigated. The grade and limitation of adulteration of the honey samples also were checked. The moisture, ash and pH were carried out. The Fourier Transform Infrared Spectroscopy (FTIR) of different samples were analyzed. The result of FTIR spectroscopy provides reliable results.

Interactions of natural colloids with microplastics in aquatic environment and its impact on FTIR characterization of polyethylene and polystyrene microplastics

The demand for plastics is expected to rise due to the exponential growth of the manufacturing sector. The plastic industries get subsidies from Governments to boost foreign exchange. The mismanagement of plastic waste has contaminated water bodies with macro, micro, and nano plastics ultimately causing varied toxicological impairment to the aquatic and terrestrial environments. We have investigated the interaction of polystyrene (PS) and polyethylene (PE) microplastics with the natural colloids in waters. Eco-corona formation due to adsorption of colloids and dissolved contaminants on the microplastic’s surface was observed upon suspending PS and PE microplastics in natural marine and freshwater tagged with 2 µg ml−1 acridine orange. Fourier transform infrared spectroscopy (FTIR) studies revealed a diminishing intensity in the characteristic peaks of the and the disappearance of minor vibrations in IR spectra of the polymers upon suspension in natural waters for over 40 days. The alterations in the peaks were restored, and PE was recovered upon treatment with 30 % hydrogen peroxide (H2O2). In contrast, the recovery of PS was only partial, denoting the strong interactions of PS with natural colloids. The active groups on the polymer structure interacting with the colloids creates an eco-corona layer absorbing the light. The ecocorona formation hinders light transmission and detection by analytical methods such as FTIR, thereby substantiating the lower quantities of PS isolated and detected from aquatic animals and environmental samples. Eco-coronated microplastics could mimic the natural feed for small fishes and lower marine animals, facilitating their uptake and further transfer across the aquatic food web.

Synthesis of Nickel Oxide Nanoparticles and Copper-Doped Nickel Oxide Nanocomposites Using Phytolacca dodecandra L'Herit Leaf Extract and Evaluation of Its Antioxidant and Photocatalytic Activities.

Nanotechnology research is emerging as cutting-edge technology, and nanoparticles (NPs) and nanocomposites (NCs) have played a significant role in the bioremediation and treatment of polluted water by organic and nonorganic materials. Nanoparticles produced by plant extracts are more stable and biocompatible in comparison with those produced by physical and chemical methods. This research focuses on the synthesis of NiO NPs and Cu-NiO NCs using Phytolacca dodecandra L'Herit (P.d) leaf extract and evaluation of their antioxidant and photocatalytic activities. Cu-NiO NCs were synthesized using 50 mL of 0.1 M nickel(II) nitrate hexahydrate, 10 mL of 0.1 M copper(II) nitrate trihydrate, and 20 mL of leaf extract. The synthesized nanoparticles were characterized by UV-vis, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) analyses to study the energy band gap, average crystallite size, functional groups, and morphology of the samples, respectively. The UV-vis analysis showed a red shift after copper doping, indicating a decrease in the optical band gap values. FT-IR characterization confirms the presence of various functional groups in samples. Crystallite sizes of the formed particles were obtained to be 14.18 and 16.10 nm from the XRD data for NiO NPs and Cu-NiO NCs, respectively. SEM showed the crystallinity of particles with a cubic structure. The photocatalytic degradation of methylene blue (MB) was found to be 78.3 and 97.8% by NiO NPs and Cu-NiO NCs, respectively. In the antioxidant test, NiO NPs and Cu-NiO NCs prevented the oxidation of 50% of the H2O2 molecules at a concentration of 363.96 and 350.29 μg/mL, respectively. Finally, the synthesized samples showed good photocatalytic and antioxidant activities.

Isolation, characterization and identification of bioactive compounds from Herbal Medicines and Medicinal Plant Extracts by Fourier Transform Infrared Spectroscopy: A brief review

Herbal medicines are mostly used from thousands of years in primary health care of society and community of both developed and developing countries. It mainly includes whole plant, herbs, extracts, isolated compounds, polyherbal preparations, phytoformulations etc. Identification of bioactive compounds from phytomedicines plays a very important role in drug development and drug design process. The characterization of phytomedicines is very much essential in the identification of compounds. For the purpose of identification two methods, Spectroscopy and Chromatography play important role. Fourier Transform Infrared Spectroscopy (FTIR) is the widely used technique which is mainly used to identify functional groups in herbal medicines. Various scientific research articles published on extraction, isolation, characterization and identification of phytoconstituents from medicinal plants and other forms of herbal medicines is being reviewed in this article. We have mainly focused on the FTIR characterization and identification of phytochemicals from herbal medicines and are briefly presented in this review work. Our present review article concludes that the FTIR spectroscopy plays very much essential role in the identification and characterization of bioactive compounds from herbal medicines.

"One-pot" preparation of aminated carbon nanotube-modified magnetic nanoparticles and their application to the quantification of phenoxyacetic acid herbicides in cereal and vegetable samples

有效萃取是分析复杂样品中苯氧羧酸类除草剂(PAs)残留的关键步骤。为此,该文利用“一锅法”水热技术快速、简便地制备了氨基碳纳米管功能化磁性纳米粒子(NH2-CNTs@M)并作为磁固相萃取(MSPE)的萃取介质,用于萃取谷物和蔬菜样品中痕量PAs。研究利用多种手段对NH2-CNTs@M的形貌、尺寸、磁性性质等进行了表征,结果表明Fe3O4的粒径、氨基化碳纳米管的直径以及NH2-CNTs@M的磁饱和值分别为30 nm、40 nm和44.2 emu/g。详细考察了制备条件和萃取参数对NH2-CNTs@M/MSPE萃取性能的影响,结果表明,NH2-CNTs@M/MSPE可通过π-π、疏水和氢键作用有效富集目标化合物,最佳萃取条件如下:吸附剂用量为30 mg,解吸溶剂为含2.0%(v/v)甲酸的乙腈溶液,吸附时间和解吸时间分别为8.0 min和3.0 min,基底pH值为6.0,不调节基底的离子强度。将NH2-CNTs@M/MSPE与高效液相色谱-二极管阵列检测技术(HPLC-DAD)联用,建立了谷物和蔬菜中PAs的灵敏检测方法。谷物和蔬菜基质中苯氧羧酸类除草剂的检出限(LOD, S/N=3)分别为0.32~1.6 μg/kg和0.53~1.6 μg/kg,定量限(LOQ, S/N=10)分别为0.94~4.8 μg/kg和1.6~4.8 μg/kg。在两种实际样品中不同浓度下的加标回收率分别为73.1%~112%和72.3%~113%。与现有方法相比,所建方法具有萃取速度快、灵敏度高和环境友好等特点。