FTIR Spectrometer Research Articles

Investigation into the crystallization of poly-lactic acid following the application of a novel high molecular weight, high epoxy functionality polymer chain extender

Abstract This research explored the impact of a novel polymer chain extender with high epoxy functionality on the crystallization properties of polylactic acid (PLA). FT-IR and Raman spectrometer were utilized to characterize the structure of PLA after chain extension. The dosage of the chain extender (HSMG) in PLA was varied to investigate its effect on the crystallization behavior of PLA via differential scanning calorimetry (DSC), polarized optical microscopy (POM), and X-ray diffraction analysis (XRD). The results indicated that incorporating HSMG into PLA significantly altered its crystallization behavior, without significantly changing its crystal structure.

Absorption coefficientofco2and first-order approximation of radiative forcing

CO2 is one of the two primary greenhouse gasses and the source of carbon needed for photosynthesis and life on Earth. The spectral absorption coefficient ?(?)[m-1] is a fundamental property of CO2.It is required for modeling heat transfer at high temperature in furnaces, heat engines, wild fire etc. and in the atmosphere at ~300 K. Using a FTIR spectrometer, infrared absorbance A(?) spectra of CO2were measured with 0.5 cm-1resolution. All measurements were conducted at 295 K. The spectra cover the wavelength range 2 ?m<?<18.2?m and the pressure range 0.04 atm<p<3atm. The spectra were used to determine the spectral absorption coefficient ?(?) in the bands adjacent to the peaks 2.7 ?m, 4.26?m and 15?m. The spectraofCO2in air are also presented. A first-order approximation-model of the radiative forcing, ?q, is presented. The FTIR spectra confirm that 400 ppm of CO2is sufficient to saturate absorption in the central PQR region of the 15 ?m band. Consequently, radiative forcing is controlled by the wings(edge) regions of the 15 ?m band. 100 % increase inCO2concentration will cause radiative forcing, ?q400ppm to 800ppm=2.79Wm-2,andtemperature increase ?T~ 0.7K. Tenfold (1000 %)increase in CO2concentrationwill increase radiative forcing by ~ 1.8x, so that ?q400ppm to 4000ppm=5.03 Wm-2and ?T~ 1.2 K.

Characterization of flavor profiles of wines produced with Coniella vitis-infected grapes by GC-MS, HPLC, and sensory analysis.

Grapevine white rot is a fungal disease that frequently occurs during the growing season, resulting in reduced fruit quality and severe yield losses. This work aimed to compare the differences in flavor profiles between wines made from different percentages of Coniella vitis-infected grapes by using FTIR spectrometer, sensory analysis, HS-SPME-GC-MS and HPLC-DAD. C. vitis infection significantly increased the soluble solids, glycerol and glucuronic acid contents, decreased the ethanol, malic and tartaric acid contents, altered the sensory characteristics of wines. Volatile phenolics, i.e., phenol, 4-ethylphenol and 4-ethylguaiacol, were the most significant difference volatile organic compounds of C. vitis infection, and methyl octanoate could be considered as an early marker of infection. C. vitis infection significantly increased most phenolic compounds contents and improved the antioxidant capacity of wine. This study would provide some new insights to understand the effect of grapevine white rot on characteristics flavor profiles of wines.

Classification of idiopathic recurrent spontaneous miscarriage using FTIR and Raman spectroscopic fusion technology

Recurrent spontaneous miscarriage refers to the repeated loss of two or more clinically detected pregnancies occurring within 24 weeks of gestation. No identifiable cause has been identified for nearly 50% of these cases. This group is referred to as idiopathic recurrent spontaneous miscarriage (IRSM) or miscarriage of unknown origin. Due to lack of robust scientific evidence, guidelines on the diagnosis and management of IRSM are not well defined and often contradictory. This motivates us to explore the vibrational fingerprints of endometrial tissue in these women. Endometrial tissues were collected from women undergoing IRSM (n = 20) and controls (n = 20) corresponding to the window of implantation. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectra were obtained within the range of 400–4000 cm−1 using Agilent Cary 630 FTIR spectrometer. Raman spectra were also generated within the spectral window of 400–4000 cm−1 using Thermo Fisher Scientific, DXR Raman spectrophotometer. Based on the limited molecular information provided by a single spectroscopic tool, fusion strategy combining Raman and ATR-FTIR spectroscopic data of IRSM is proposed. The significant features were extracted applying principal component analysis (PCA) and wavelet threshold denoising (WTD) and fused spectral data used as input into support vector machine (SVM), adaptive boosting (AdaBoost) and decision tree (DT) models. Altered molecular vibrations associated with proteins, glutamate, and lipid metabolism were observed in IRSM using Raman spectroscopy. FTIR analysis indicated changes in the molecular vibrations of lipids and proteins, collagen dysregulation and impaired glucose metabolism. Combination of both spectroscopic data using mid-level fusion (MLF: 92% using AdaBoost and DT models) and high-level fusion (HLF: 92% using SVM models) methods showed improved IRSM classification accuracy as compared to individual spectral models. Our results indicate that spectral fusion technology hold promise in enhancing diagnostic accuracy of IRSM in clinical settings. Validation of these findings in a larger patient population is underway.

Fourier Transform Infrared Spectroscopy (FTIR) Spectral evaluation in Chrysanthemum flower species

The current study's goal was to identify the various functional groups found in chrysanthemums using FTIR Spectroscopy. The FTIR spectrometer identifies 4000 series, with a scan range of 4,000–400 cm-1, was used to perform the FTIR analysis. The presence of distinct peak values with various useful mixtures of functional groups, including hydroxy groups (̶ OH), aliphatic, metal carbonyl, alcohols (̶ OH), nitrile (̶ C≡N), phenols, alkynes (CnH2n-2), ketones (C=O), carboxylic acids (R−COOH), amides (̶ CONH2), and aromatics, was revealed by FTIR spectroscopy analysis. The FTIR investigation showed that there were 17 functional groups in the chrysanthemum flowers. The FTIR spectra showed an intense peak that correlated to the hydroxyl groups, phenol alcohol, and aromatic compounds, respectively, at 3348.42 cm-1, 1380.02 cm-1, and 1480.33 cm-1 in various flower species. In light of this, the current investigation found that, in contrast to the extracts of Chrysanthemum flowers' leaves and bark, the flower extract had robust functional groups. FTIR spectroscopy was used to quantitatively analyse the flavonoids, phenolic acids, anthocyanins, and carotenoids present in the nine chrysanthemum cultivars' flowers.

5-Bromo-N′-(2-oxoindolin-3-ylidene)furan-2-carbohydrazide

5-Bromo-N′-(2-oxoindolin-3-ylidene)furan-2-carbohydrazide (1) was successfully synthesized in 79.4% yield by reaction of isatin with 5-bromofuran-2-carbohydrazide in acidic conditions under reflux. The structure of synthesized compound 1 was confirmed by 1H and 13C NMR, FTIR, and HRMS spectrometers. It is necessary to evaluate compound 1 as an anti-inflammatory agent.

Profile distribution, Z-scan technique, Optical limiting and thermal lens method studies on Cyanidin-3-O-glucoside chloride.

For the purpose of determining the characteristics of the Cyanidin-3-O-glucoside chloride (COGC) dye, both an FT-IR spectrometer and a UV-Visible spect rometer were employed through the process. At a wavelength of 473nm, a diode-pumped solid-state (DPSS) laser with an adjustable wavelength was used to quantify the thermally induced optical nonlinearity of the dye in a solvent composed of dimethylformamide. For the purpose of measuring the optical response, the Z-scan technique was utilised. The dye showed negative and large nonlinear index of refraction values, with high nonlinear absorption coefficients. The nonlinear index of refraction ( ) and nonlinear absorption coefficient (β) of the COGC/PMMA film were measured to be 110.55 × 107 cm2/W and 136.35 × 10-3cm/W. Thermal lens technique was used to investigate thermo-optical properties and . The optical limiter capabilities of the COGC dye are being investigated as a potential use.

Research on infrared spectral characteristics and rapid detection technology of industrial hemp

Objective: The aim of this study was to research the infrared spectroscopic features of various industrial hemp samples, establish a rapid infrared detection method for industrial hemp based on cannabidiol (CBD) content, and utilize infrared spectroscopy to differentiate industrial hemp flowers and leaves from different varieties and origins. Methods: Appropriate preprocessing was conducted on the industrial hemp samples based on their inherent characteristics. The samples were then scanned using the FTIR spectrometer, with careful subtraction of the background spectrum. A semi-quantitative rapid detection method for flowers and leaves using infrared spectroscopy was developed through partial least squares discriminant analysis. Data processing software was used to conduct principal component analysis and cluster analysis on the transmittance values of infrared characteristic absorption peaks, aiding in the identification and differentiation of samples from different varieties, origins, and harvest dates. Results: A semi-quantitative rapid detection method for industrial hemp flowers and leaves based on CBD content was successfully developed. Principal component analysis was able to clearly distinguish industrial hemp of different varieties and origins, effectively clustering samples of the same variety. This underscores the significant impact of mid-infrared spectroscopy in the identification and analysis of industrial hemp, providing an innovative approach to quickly identifying different hemp varieties.

Antioxidant Release Profile from Chitosan/ĸ-Carrageenan-based Polyelectrolyte Complex Films as Active Packaging: A Preliminary Study

Significant efforts are necessary to prevent the spoilage of fatty acid-rich foods as a result of lipid oxidation. Active packaging is a technology that employs packaging films containing antioxidants to increase the stability of perishable foods susceptible to oxidation. This preliminary study aimed to incorporate tannic acid (TA) into a chitosan/κ-carrageenan (Chit/κ-Car)-based polyelectrolyte complex (PEC) films and evaluate their antioxidant release profile. The composition of Chit/κ-Car, glycerol (gly), and TA in PEC films were also investigated in this preliminary study as factors influencing the mechanical properties of films and the antioxidant release profile. The prepared PEC films were identified by an FTIR spectrometer and examined through a mechanical property test. The DPPH method was used to assess the antioxidant property of the Chit/κ-Car-based PEC films. The infrared spectra revealed that PEC films were formed through the interaction between ꟷNH3+ of Chit and ꟷOSO3ꟷ of κ-Car. Increasing the κ-Car and TA compositions in the PEC films increased the tensile strength (TS) and water absorption capacity (WAC), but decreased the elongation (E). The release profile of TA from PEC films followed the Korsmeyer-Peppas model through the Fickian diffusion mechanism with n < 0.5. The antioxidant activity test of PEC films using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method revealed high antioxidant activity with radical scavenging activity (RSA) values up to 95.04%. As a result, the Chit/κ-Car-based PEC films have the potential to be developed as active packaging. Keywords: Active packaging, antioxidant, Chit/κ-Car-based PEC films, release profile, TA

Extraction of Lignocellulose from Rice Straw and Its Carboxymethylation When Activated by Microwave Radiation.

The paper presents the process of cellulose extraction from rice straw using water-alkaline solution treatment and the subsequent process of carboxymethylation of the obtained product when activated by microwave radiation. After mercerization of rice straw, the obtained product contained 89.2% cellulose and 6.7% lignin. The X-ray diffraction pattern of the obtained lignocellulose shows three diffraction peaks in the region typical for the polymorphic modification of cellulose Iβ (2θ = 15.50(78), 21.70(145), 34.70(52)). The degree of crystallinity was 65%. The product was heat-stable up to 247 °C. The synthesis of carboxymethylcellulose (CMC) based on the obtained product included successive processes of thermostating in alcohol-alkali solution and cellulose esterification reaction using monochloroacetic acid. To activate the carboxymethylation process, microwave radiation was used (350 W for 90 s), which made it possible to reduce the reaction time by more than 100 times. Functional group analysis of the carboxylated lignocellulose from rice straw was carried out using an FTIR spectrometer. In the IR spectra, a band with a maximum of 1742 cm-1 was recorded, corresponding to stretching vibrations of >C(O)OH groups. The degree of polymerization was recorded by mass spectrometry.

Enhancement of 5-Fluorouracil Drug Delivery in a Graphene Oxide Containing Electrospun Chitosan/Polyvinylpyrrolidone Construct.

Electrospun nanofibrous mats, consisting of chitosan (CS) and polyvinylpyrrolidone (PVP), were constructed with the addition of graphene oxide (GO) for enhancement of delivery of the 5-Fluorouracil (5-Fu) chemotherapy drug. Upon studying the range of GO concentrations in CS/PVP, the concentration of 0.2% w/v GO was chosen for inclusion in the drug delivery model. SEM showed bead-free, homogenous fibres within this construct. This construct also proved to be non-toxic to CaCo-2 cells over 24 and 48 h exposure. The construction of a drug delivery vehicle whereby 5-Fu was loaded with and without GO in various concentrations showed several interesting findings. The presence of CS/PVP was revealed through XPS, FTIR and Raman spectroscopies. FTIR was also imperative for the analysis of 5-Fu while Raman exclusively highlighted the presence of GO in the samples. In particular, a detailed analysis of the IR spectra recorded using two FTIR spectrometers, several options for determining the concentration of 5-Fu in composite fibre systems CS/PVP/5-Fu and GO/CS/PVP/5-Fu were demonstrated. By analysis of Raman spectra in the region of D and G bands, a linear dependence of ratios of integrated intensities of AD and AG on the intensity of host polymer band at 1425 cm-1 vs. GO content was found. Both methods, therefore, can be used for monitoring of GO content and 5-Fu release in studied complex systems. After incorporating the chemotherapy drug 5-Fu into the constructs, cell viability studies were also performed. This study demonstrated that GO/CS/PVP/5-Fu constructs have potential in chemotherapy drug delivery systems.

Piezo-optical properties and infrared spectra of Rb2SO4 crystals

The paper deals with the dispersion dependences of birefringence Δni(λ) of the mechanically free and uniaxially clamped Rb2SO4 crystal along different crystal-physical axes at room temperature. It was found that the crystal has an insignificant normal dispersion d(Δnx)/dλ χ ≤ 0, and uniaxial compressions σm do not change the character, but only the slope of the dependences Δni(λ). Uniaxial loads shift the position of the optical isotropic point both in the short-wavelength (σz) and in the long-wavelength part of the spectrum (σy). The spectral dependences of the combined piezo-optical coefficients πkmo(λ) were calculated and it was found that they have an insignificant dispersion dependence, and the absolute values of the piezo-optical coefficients π31o and π21o are equal to each other in the vicinity of the optical isotropic point at the light wavelength λ = 490 nm. The reflection spectra of Rb2SO4 crystals were measured in the infrared range at room temperature using FT-IR spectrometer and synchrotron radiation and the corresponding ab initio calculations of the phonon partial density of states and the dielectric function were performed.

Studies of third order nonlinearity and thermal diffusivity of C3OC dye using thermal lens technique

An FT-IR spectrometer and a UV–Visible spectrometer were utilised in order to characterise the Cyanidin-3-O-glucoside chloride (C3OC) dye. The dye’s thermally induced optical nonlinearity was measured in a dimethylformamide solvent using an adjustable diode-pumped solid-state (DPSS) laser at 473 nm. The optical response was measured using the Z-scan technique. The dye showed negative and large nonlinear refractive index) NRX) values, with high nonlinear absorption coefficients (NBO). Because of its ability to change with concentration, the NRX is a viable candidate for applications in the field of nonlinear optics. Thermal lens (THS) technique was used to investigate thermo-optical properties and the NRX. The optical limiter capabilities of the C3OC dye are being investigated as a potential use.

The Investigation of Structural, Optical and Thermal Properties of Nickel Doped CeO2 Integrated PVC Nanocomposite.

PVC nanocomposite (NC) films with cubic CeO2 and Ni-doped CeO2 (NDC) have been prepared using a conventional solution-casting technique. The prepared films were characterized with FT-IR spectrometer, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The optical and thermal properties of the films were evaluated using a UV-visible spectrophotometer and TGA/DSC. The optical study revealed a decrease in optical band gap energies (4.19 to 4.06 eV) whereas the increase in other optical constraints such as optical conductivity, Urbach energy, dispersion energy, refractive index, and dielectric constant of PVC NCs than pristine PVC was observed. The XRD patterns showed the presence of cubic crystalline NDC with a relatively narrower principal diffraction peak in the PVC matrix and the nonexistence of unexpected vibrational peaks in the FTIR spectra of PVC NCs confirmed the successful incorporation of nanostructured CeO2 and NDC into PVC. Thermogravimetric analysis showed the higher thermal stability of NDC/PVC NC than PVC whereas differential scanning calorimetry declared no significant change in the glass transition temperature (Tg) of the NCs. Moreover, a good dispersion of Ni-doped CeO2 nanofiller was noticed in scanning electron micrographs.

Molecular profiling of blood plasma-derived extracellular vesicles derived from Duchenne muscular dystrophy patients through integration of FTIR spectroscopy and machine learning reveals disease signatures

PurposeTo identify and monitor the FTIR spectral signatures of plasma extracellular vesicles (EVs) from Duchenne Muscular Dystrophy (DMD) patients at different stages with Healthy controls using machine learning models. Materials and methodsWhole blood samples were collected from the DMD (n = 30) and Healthy controls (n = 12). EVs were extracted by the Total Exosome Isolation (TEI) Method and resuspended in 1XPBS. We characterize the morphology, size, particle count, and surface markers (CD9, Alix, and Flotillin) by HR-TEM, NTA, and Western Blot analysis. The mid-IR spectra were recorded from (4000–400 cm−1) by Bruker ALPHA II FTIR spectrometer model, which was equipped with an attenuated total reflection (ATR) module. Machine learning algorithms like Principal Component Analysis (PCA) and Random Forest (RF) for dimensionality reduction and classifying the two study groups based on the FTIR spectra. The model performance was evaluated by a confusion matrix and the sensitivity, specificity, and Receiver Operating Characteristic Curve (ROC) was calculated respectively. ResultsAlterations in Amide I & II (1700–1470 cm−1) and lipid (3000–2800 cm−1) regions in FTIR spectra of DMD compared with healthy controls. The PCA-RF model classified correctly the two study groups in the range of 4000–400 cm−1 with a sensitivity of 20 %, specificity of 87.50 %, accuracy of 71.43 %, precision of 33.33 %, and 5-fold cross-validation accuracy of 82 %. We analyzed the ten different spectral regions which showed statistically significant at P < 0.01 except the Ester Acyl Chain region. ConclusionOur proof-of-concept study demonstrated distinct infrared (IR) spectral signatures in plasma EVs derived from DMD. Consistent alterations in protein and lipid configurations were identified using a PCA-RF model, even with a small clinical dataset. This minimally invasive liquid biopsy method, combined with automated analysis, warrants further investigation for its potential in early diagnosis and monitoring of disease progression in DMD patients within clinical settings.

STUDY OF METHODS FOR ACTIVATING BENTONITE CLAY FROM THE DARBAZA DEPOSIT

In our country, the problem of water treatment remains urgent, and this is facilitated by the growth of external factors, which can include the increase in the number of industrial enterprises, agricultural development, urban growth and others. Objective. To solve the problem of wastewater treatment it is economically advantageous to create new sorbents, from the resources available in our country. Instrumental test methods were chosen for bentonite clay treatment under experimental conditions using scanning electron microscope (SEM) Jeol JSM-6490l V, FTIR spectrometer NEXUS E.S.P. (Thermo Scientific, USA), laser particle size analyser Analizette 22 MicroTec (Fritsch GmbH, Germany). According to the results of instrumental studies, the elemental and mineralogical composition of bentonite clay from Darbazi deposit was determined using scanning scanning electron microscope and FTIR spectrometer. The obtained sorbent on the basis of bentonite clay has a high sorption capacity and is recommended to be used in wastewater treatment of chemical industries. The obtained sorbent on the basis of bentonite clay from Darbazinsky deposit allows to purify wastewater of various productions containing ions of heavy metals up to 95%. The developed sorbent on the basis of bentonite clay has ecological and economic efficiency, connection with the use of local natural resources. Thus, it should be noted that for adsorptive treatment of wastewater from chemical industries with a high degree it is possible to use effective sorbents based on bentonite clays of Darbaza deposit. It should also be noted that the use of bentonite clays for water treatment by sorption process is an effective and affordable alternative to adsorbents, which show high adsorption capacity in relation to various compounds.

The process of evaporation of a colloidal solution of stabilized Boron nitride nanoparticles

Purpose. Characterization of the chemical structure of boron nitride nanoparticles by IR spectroscopy during the evaporation of their colloidal system and their sizes by small-angle X-ray scattering.Methods. The solvent evaporation process from the colloidal system was studied using a Nicolet iS 50 FT-IR spectrometer in the mid-IR range (400 – 4000 cm-1), with an attenuated total reflectance accessory with a diamond crystal (incident angle of 45°) and a liquid cell (200 μL). The sizes of the colloidal particles were determined using an smallangle X-ray scattering diffractometer in linear collimation mode (resolution 0.03 nm-1, copper anode X-ray tube 2.2 kW, λ = 0.154 nm, exposure time 30 s).Results. The IR spectrum of boron nitride nanoparticles powder was measured, containing lines characteristic of cubic (952 cm-1) ) – c-BN and hexagonal crystalline phases (758, 1301, and 1372 cm-1) – h-BN. The average size of boron nitride nanoparticles in the colloidal system, according to small-angle X-ray scattering data, was 46 and 84 nm. The size of stearic acid, which acts as a stabilizing shell, was 0.8, 1.3, and 2.5 nm. Analysis of the IR spectra showed complete evaporation of the solvents (hexane and chloroform) from a drop of colloidal solution 1.2 mm thick within 30 minutes.Conclusion. In this work, the average sizes of boron nitride nanoparticles stabilized with stearic acid in a colloidal system were determined and the process of its evaporation was studied.

Innovative Method of Biomass Combustion in the Binary Fluidised Bed

Abstract In this study, a binary fluidised bed made out of quartz sand and cenospheres for the biomass combustion process was created. Materials were fluidised with air to achieve a vertical density profile (from 0.5 g/cm³ to 1.1 g/cm³) resulting from grains segregation. The density profile was selected to ensure optimal control over the location of the combusted fuel particle. This involved positioning the process as close to the bottom sieve as possible. Fluidised bed combustion was carried out at temperatures of 600 °C, 700 °C, 820 °C and 870 °C using straw, willow and sawmill pellets as fuels. Qualitative and quantitative analysis of flue gases was performed using an FTIR spectrometer. Over 90 % carbon conversion from the biomass to carbon dioxide was achieved at 700 °C. At 820 °C and 870 °C, 100 % of biomass carbon left the reactor as CO2. The composition of organic compounds in the process products remained low, reaching a maximum of 3.0 % wt. at 600 °C. To gain further insights into the processes occurring in the immediate vicinity of biomass samples, a complementary TGA/FTIR analysis was conducted. This aimed to clarify the impact of the biomass particle decomposition stage in the fluidised bed combustion process. The proposed mechanism for biomass combustion in the binary fluidised bed contains the particle decomposition stage and the subsequent stage resulting from the coalescence of bubbles containing flammable components and bubbles containing oxidiser.

Remediation of Arsenic and Heavy Metals and Soil Stabilization by Waste Chitosan based Biochar

Objectives : This study aims to evaluate the feasibility of converting waste chitosan adsorbents, laden with microalgae, into biochar for application as a stabilizing agent to remediate heavy metal-contaminated soil and improve soil quality.Methods : Waste chitosan adsorbents were converted into biochar through two processes: dry thermal carbonization at 400°C to produce pyrochar and hydrothermal carbonization at 200°C to produce hydrochar. The elemental compositions, surface functional groups, morphologies of the biochars were evaluated by elemental analyzer, FT-IR spectrometer, and SEM analysis. The arsenic and heavy metal adsorption characteristics of the produced biochars were assessed. Additionally, the produced biochars were applied as stabilizing agents to arsenic and heavy metal-contaminated soil with varying mixing ratios of 2, 5 and 10 wt%. After a one-week soil stabilization experiment, soil properties and TCLP(Toxicity Characteristic Leaching Procedure) leaching tests were conducted.Results and Discussion : The pyrochar produced from waste chitosan exhibited a porous structure with high pH (pH 10) and minimal surface functional groups. The hydrochar consisted of spherical particles with functional groups such as hydroxyl and amine groups on the surface, exhibiting a slightly acidic pH of 5.8. Pyrochar has a higher adsorption capacity for cationic heavy metals compared to hydrochar due to its porous structure and high pH. On the other hand, when applied to soil, hydrochar demonstrated superior stabilization efficiency for arsenic and heavy metals. This is attributed to the diverse surface functional groups containing oxygen on the hydrochar. The stabilization efficiency was influenced by the biochar mixing ratio, with a 5% hydrochar application resulting in 10-64% stabilization efficiency for all elements.Conclusion : This study confirmed that biochar produced from waste chitosan effectively stabilizes arsenic and heavy metals in soils. Additionally, the quantity of biochar used can impact its effectiveness in stabilization.

Synthesis of Novel Ester-Based 5-Fluorouracil Derivatives

Fluorouracil (5-Fu, 1) is an antimetabolite cancer drug and the first-line drug of anticancer administration by WHO that has been widely used worldwide for more than 50 years. The development of 5-fluorouracil is an effort to obtain higher activity, decrease side effects, and create a specific target receptor compared to 5-fluorouracil. In this research, a series of novel 5-Fluorouracil (5-Fu) derivatives has been synthesized based on a benzoylation reaction (Schotten-Baumann reaction) of N1-hydroxylated 5-Fu called compound 2, 5-fluoro-1-(hydroxymethyl)-uracil. The benzoyl chloride substituents used in this research, including 3-chlorobenzoyl (4a), 2-chlorobenzoyl (4b), 3-nitrobenzoyl (4c), 4-methoxy benzoyl (4d), 4-trifluoromethylbenzoyl (4e), 3,4-dichlorobenzoyl (4f), and 4-nitrobenzoyl (4g) chloride become (4a-4f)-5Fu. This research meticulously examined the conditions (time and reaction temperature) at the second step of the synthesis reaction (esterification), ensuring the reliability of the results. The best synthesis conditions for 4a, 4b, 4c, 4d, and 4g compounds were found to be reflux at 40°C for 6 hours, whereas 4e and 4f compounds reactions were performed in an ice bath for 11 and 17 hours, respectively. All product syntheses, 4a-4g compound, were purified using column chromatography and eluted using eluent hexane: acetone (6:4), and the yields of 4a-4g compounds were around 61-79%. The pure compounds were characterized using FTIR and 1HNMR spectrometer, further validating the research. Based on these findings, it can be concluded that all 5-Fu derivatives can be synthesized using the Schotten-Baumann reaction method.