Displaying publications 21 - 40 of 1022 in total

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  1. Kiong TC, Nordin N, Ahmad Ruslan NAA, Kan SY, Ismail NM, Zakaria Z, et al.
    Environ Res, 2022 Oct;213:113737.
    PMID: 35752328 DOI: 10.1016/j.envres.2022.113737
    To keep COVID-19 at bay, most countries have mandated the use of face masks in public places and imposed heavy penalties for those who fail to do so. This has inadvertently created a huge demand for disposable face masks and worsened the problem of littering, where a large number of used masks are constantly discarded into the environment. As such, an efficient and innovative waste management strategy for the discarded face mask is urgently needed. This study presents the transformation of discarded face mask into catalyst termed 'mask waste ash catalyst (MWAC)' to synthesise bisindolylmethanes (BIMs), alkaloids that possess antibacterial, antioxidant and antiviral properties. Using commercially available aldehydes and indole, an excellent yield of reaction (62-94%) was achieved using the MWAC in the presence of water as the sole solvent. On the other hand, the FT-IR spectrum of MWAC showed the absorption bands at 2337 cm-1, 1415 cm-1 and 871 cm-1, which correspond to the signals of calcium oxide. It is then proposed that the calcium oxides mainly present in MWAC can protonate oxygen atoms in the carbonyl molecule of the aldehyde group, thus facilitating the nucleophile attack by indole which consequently improved the product yield. Moreover, the MWAC is also observed to facilitate the photodegradation of methylene blue with an efficiency of up to 94.55%. Our results showed the potential applications of the MWAC derived from discarded face masks as a sustainable catalyst for bioactive compound synthesis and photodegradation of dye compounds.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  2. Mohamed Saadon NAF, Taib NI, Loy CW, Mohamed Z
    Sci Rep, 2023 Jan 23;13(1):1246.
    PMID: 36690692 DOI: 10.1038/s41598-023-28296-7
    In this paper, Sr2-xCaxNiWO6 (x = 0.00, 0.02, 0.04, 0.06) were synthesized using a solid-state reaction method. The crystal structure, optical and dielectric properties of the compounds were examined using X-ray diffraction (XRD), scanning electron microscope (SEM) with energy dispersive (EDX) analysis, Ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy and electrochemical impedance spectroscopy respectively. The Rietveld refinement of XRD confirmed that the compounds crystallized in a tetragonal structure with a space group I4/m. According to the SEM images, the grain sizes of the compounds decreased as the dopant increased. The UV-vis analysis revealed that the band gap energy of the compounds decreased from 3.17 eV to 3.13 eV as the amount of doping increased from x = 0.00 to x = 0.06. A dielectric characterization showed that the dielectric constant (ε') and dielectric loss (tan δ) for all compounds possessed a similar trend where it was higher in low-frequency area (~ 1 Hz) and dropped instantaneously with the enhancement of frequency up to 1 MHz until it reached constant values.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  3. Adeleke AO, Royahu CO, Ahmad A, Dele-Afolabi TT, Alshammari MB, Imteaz M
    PLoS One, 2024;19(2):e0294286.
    PMID: 38386950 DOI: 10.1371/journal.pone.0294286
    This study highlights the effectiveness of oyster shell biocomposite for the biosorption of Cd(II) and Pb(II) ions from an aqueous solution. The aim of this work was to modify a novel biocomposite derived from oyster shell for the adsorption of Cd(II) and Pb(II) ions from aqueous solution. The studied revealed the specific surface BET surface area was 9.1476 m2/g. The elemental dispersive x-ray analysis (EDS) indicated that C, O, Ag, Ca were the predominant elements on the surface of the biocomposite after which metals ions of Cd and Pb were noticed after adsorption. The Fourier transform Irradiation (FT-IR) revealed the presence of carboxyl and hydroxyl groups on the surface. The effect of process variables on the adsorption capacity of the modified biocomposite was examined using the central composite design (CCD) of the response surface methodology (RSM). The process variables which include pH, adsorbent dose, the initial concentration and temperature were the most effective parameters influencing the uptake capacity. The optimal process conditions of these parameters were found to be pH, 5.57, adsorbent dose, 2.53 g/L, initial concentration, 46.76 mg/L and temperature 28.48°C for the biosorption of Cd(II) and Pb(II) ions from aqueous solution at a desirability coefficient of 1. The analysis of variance (ANOVA) revealed a high coefficient of determination (R2 > 0.91) and low probability coefficients for the responses (P < 0.05) which indicated the validity and aptness of the model for the biosorption of the metal ions. Experimental isotherm data fitted better to the Langmuir model and the kinetic data fitted better to the pseudo-second-order model. Maximun Cd(II) and Pb(II) adsorption capacities of the oyster shell biocomposite were 97.54 and 78.99 mg/g respectively and was obtained at pH 5.56 and 28.48°C. This investigation has provided the possibility of the utilization of alternative biocomposite as a sustainable approach for the biosorption of heavy metal ions from the wastewater stream.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  4. Lim CC, Shuit SH, Ng QH, Rahim SKEA, Hoo PY, Yeoh WM, et al.
    Environ Sci Pollut Res Int, 2023 Mar;30(14):40242-40259.
    PMID: 36604398 DOI: 10.1007/s11356-022-25064-4
    In view of the simple and rapid conveniency of magnetic separation, magnetic nanocomposites had notably gained attention from researchers for environmental field applications. In this work, carboxylated magnetic multi-walled carbon nanotubes (c-MMWCNTs) and novel sulfonated MMWCNTs (s-MMWCNTs) were synthesized by a facile solvent-free direct doping method. Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, energy dispersive X-ray, vibrating sample magnetometer, and point of zero charge analyses confirmed the successful doping of the Fe3O4 nanoparticles into the functionalized MWCNTs to form MMWCNTs. Besides, the bonding stabilities of both c-MMWCNTs and s-MMWCNTs were compared, and results showed that s-MMWCNTs possessed more substantial bonding stability than that of c-MMWCNTs with significantly less leaching amount of Fe3O4. The adsorption capacity of s-MMWCNTs was higher than that of c-MMWCNTs owing to the stronger electronegativity sulfonic group in s-MMWCNTs. Moreover, the reusability experiments proved that the adsorbent remained consistently excellent MB removal efficiency (R > 94%) even reused for twelve cycles of batch adsorption. The finding of the present work highlights the simple fabrication of novel s-MMWCNTs and its potential to be served as a promising and sustainable adsorbent for water remediation owing to its enhanced bonding stability, high adsorption performance, magnetic separability, and supreme recyclability.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  5. Agatonovic-Kustrin S, Rades T, Wu V, Saville D, Tucker IG
    J Pharm Biomed Anal, 2001 Jul;25(5-6):741-50.
    PMID: 11377056
    The identification, characterization and quantification of crystal forms are becoming increasingly important within the pharmaceutical industry. A combination of different physical analytical techniques is usually necessary for this task. In this work solid-state techniques, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and X-ray powder diffractometry (XRPD) were combined to analyze polymorphic purity of crystalline ranitidine-HCl, an antiulcer drug, H2 receptor antagonists. A series of 12 different mixtures of Form 1 and 2 was prepared by geometric mixing and their DRIFT spectra and XRD powder patterns were obtained and analyzed, either alone or combined together, using Artificial Neural Networks (ANNs). A standard feed-forward network, with back-propagation rule and with multi layer perceptron architecture (MPL) was chosen. A working range of 1.0-100% (w/w) of crystal Form 2 in Form 1 was established with a minimum quantifiable level (MQL) of 5.2% and limit of detection of 1.5% (w/w). The results demonstrate that DRIFTS combined with XRPD may be successfully used to distinguish between the ranitidine-HCl polymorphs and to quantify the composition of binary mixtures of the two.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared/methods*
  6. Mirghani ME, Che Man YB, Jinap S, Baharin BS, Bakar J
    Phytochem Anal, 2002 Jul-Aug;13(4):195-201.
    PMID: 12184171
    A simple and rapid Fourier transform infrared (FTIR) spectroscopic method has been developed for the quantitative determination of malondialdehyde as secondary oxidation product in a palm olein system. The FTIR method was based on a sodium chloride transmission cell and utilised a partial least square statistical approach to derive a calibration model. The frequency region combinations that gave good calibration were 2900-2800, and 1800-1600 cm-1. The precision and accuracy, in the range 0-60 mumol malondialdehyde/kg oil, were comparable to those of the modified distillation method with a coefficient of determination (r2) of 0.9891 and standard error of calibration of 1.49. The calibration was cross-validated and produced an r2 of 0.9786 and standard error of prediction of 2.136. The results showed that the FTIR method is versatile, efficient and accurate, and suitable for routine quality control analysis with the result obtainable in about 2 min from a sample of less than 2 mL.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared/methods*
  7. Choong YK, Chen X, Jamal JA, Wang Q, Lan J
    Int J Med Mushrooms, 2012;14(3):295-305.
    PMID: 22577979
    Spaceflight represents a complex environmental condition. Space mutagenesis breeding has achieved marked results over the years. The objective of this study is to determine the chemical changes in medicinal mushroom Ganoderma lucidum cultivated after spaceflight in 1999. Fourier transform infrared (FTIR) and two-dimensional infrared (2DIR) correlation spectroscopy were used in analysis. The sample Sx and its control Cx showed the least dissimilarities in one-dimensional FTIR spectra, but absorbance of Sx is twice as high as Cx. Sx presented a clear peak at 1648 cm in 2nd derivative spectra, which could not be detected in the Cx. The 2DIR spectra showed the intensity of Sx in the range 1800-1400 cm-1 for protein is higher than the control. The sample Sx produced some carbohydrate peaks in the area of 889 cm-1 compared with the Cx. The spaceflight set up an extreme condition and caused changes of chemical properties in G. lucidum strain.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared*
  8. Sim LH, Gan SN, Chan CH, Yahya R
    Spectrochim Acta A Mol Biomol Spectrosc, 2010 Aug;76(3-4):287-92.
    PMID: 20444642 DOI: 10.1016/j.saa.2009.09.031
    The interaction behaviours between components of polyacrylate (PAc)/poly(ethylene oxide) (PEO) and lithium perchlorate (LiClO(4)) were investigated in detail by Attenuated Total Reflectance (ATR)-Fourier Transformed Infrared (FTIR) spectroscopy. Solution cast films of the PAc/PEO and PAc/PEO/LiClO(4) were examined. No obvious shifting of the characteristic ether and ester group stretching modes of PEO and PAc was observed, indicating incompatibility of the binary PAc/PEO blend. The spectroscopic studies on the PAc/PEO/LiClO(4) blends reveal that Li(+) ions coordinate individually to the polymer components at the ether oxygen of PEO and the C-O of the ester group of PAc. Frequency changes observed on the nu(C-O-C) and omega(CH(2)) of PEO confirm the coordination between PEO and Li(+) ions resulting in crystallinity suppression of PEO. The absence of experimental evidence on the formation of PEO-Li(+)-PAc complexes suggests that LiClO(4) does not enhance the compatibility of PAc/PEO blend.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared*
  9. Kadir MF, Aspanut Z, Majid SR, Arof AK
    PMID: 21237698 DOI: 10.1016/j.saa.2010.12.051
    Fourier transform infrared (FTIR) spectroscopy studies of poly(vinyl alcohol) (PVA), and chitosan polymer blend doped with ammonium nitrate (NH(4)NO(3)) salt and plasticized with ethylene carbonate (EC) have been performed with emphasis on the shift of the carboxamide, amine and hydroxyl bands. 1% acetic acid solution was used as the solvent. It is observed from the chitosan film spectrum that evidence of polymer-solvent interaction can be observed from the shifting of the carboxamide band at 1660 cm(-1) and the amine band at 1591 cm(-1) to 1650 and 1557 cm(-1) respectively and the shift of the hydroxyl band from 3377 to 3354 cm(-1). The hydroxyl band in the spectrum of PVA powder is observed at 3354 cm(-1) and is observed at 3343 cm(-1) in the spectrum of the PVA film. On addition of NH(4)NO(3) up to 30 wt.%, the carboxamide, amine and hydroxyl bands shifted from 1650, 1557 and 3354 cm(-1) to 1642, 1541 and 3348 cm(-1) indicating that the chitosan has complexed with the salt. In the PVA-NH(4)NO(3) spectrum, the hydroxyl band has shifted from 3343 to 3272 cm(-1) on addition of salt from 10 to 30 wt.%. EC acts as a plasticizing agent since there is no shift in the bands as observed in the spectrum of PVA-chitosan-EC films. The mechanism of ion migration is proposed for the plasticized and unplasticized PVA-chitosan-NH(4)NO(3) systems. In the spectrum of PVA-chitosan-NH(4)NO(3)-EC complex, the doublet CO stretching in EC is observed in the vicinity 1800 and 1700. This indicates that there is some interaction between the salt and EC.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared/methods*
  10. Ch'ng HY, Ahmed OH, Majid NM
    ScientificWorldJournal, 2011;11:532-45.
    PMID: 21403973 DOI: 10.1100/tsw.2011.54
    Logging and poor shifting cultivation negatively affect initial soil carbon (C) storage, especially at the initial stage of deforestation, as these practices lead to global warming. As a result, an afforestation program is needed to mitigate this problem. This study assessed initial soil C buildup of rehabilitated forests using Fourier transform infrared (FTIR) spectroscopy. The relatively high E4/E6 values of humic acids (HAs) in the rehabilitated forest indicate prominence of aliphatic components, suggesting that the HAs were of low molecular weight. The total acidity, carboxylic (-COOH) and phenolic (-OH) of the rehabilitated forest were found to be consistent with the ranges reported by other researchers. The spectra of all locations were similar because there was no significant difference in the quantities of C in humic acids (CHA) regardless of forest age and soil depth. The spectra showed distinct absorbance at 3290, 1720, 1630, 1510, 1460, 1380, and 1270 cm-1. Increase of band at 1630 and 1510 cm-1 from 0-20 to 40-60 cm were observed, suggesting C buildup from the lowest depths 20-40 and 40-60 cm. However, the CHA content in the soil depths was not different. The band at 1630 cm-1 was assigned to carboxylic and aromatic groups. Increase in peak intensity at 1510 cm-1 was because C/N ratio increased with increasing soil depth. This indicates that decomposition rate decreased with increasing soil depth and decreased with CHA. The finding suggests that FTIR spectroscopy enables the assessment of C composition functional group buildup at different depths and ages.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared/methods*
  11. Yusof NA, Isha A, Ismail IS, Khatib A, Shaari K, Abas F, et al.
    J Sci Food Agric, 2015 Sep;95(12):2533-43.
    PMID: 25371390 DOI: 10.1002/jsfa.6987
    The metabolite changes in three germplasm accessions of Malaysia Andrographis paniculata (Burm. F.) Nees, viz. 11265 (H), 11341 (P) and 11248 (T), due to their different harvesting ages and times were successfully evaluated by attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy and translated through multivariate data analysis of principal component analysis (PCA) and orthogonal partial least square-discriminant analysis (OPLS-DA). This present study revealed the feasibility of ATR-FTIR in detecting the trend changes of the major metabolites - andrographolide and neoandrographolide - functional groups in A. paniculata leaves of different accessions. The harvesting parameter was set at three different ages of 120, 150 and 180 days after transplanting (DAT) and at two different time sessions of morning (7:30-10:30 am) and evening (2:30-5.30 pm).
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared/methods
  12. Latiff NF, Sulaiman NF, Shaik MI, Mohamad NJ, Khairul WM, Daud AI, et al.
    J Food Sci, 2025 Mar;90(3):e70134.
    PMID: 40111016 DOI: 10.1111/1750-3841.70134
    This study developed and characterized a pH-sensitive gelatin-based film incorporated with anthocyanin from roselle extracts (Hibiscus sabdariffa) at varying concentrations (0%-15%). The addition of anthocyanins significantly influenced the film's properties, reducing tensile strength from 1.5 to 1.1 MPa while increasing elongation at break from 312% to 416%. Water vapor permeability also increased with anthocyanin concentration, ranging from 1.02 to 1.47 × 10-⁸ g·m-¹·s-¹·Pa-¹. The film displayed a distinct color change from red to yellow-green across pH 3-10 and when exposed to ammonia gas, highlighting its potential for real-time detection of volatile basic compounds. Fourier transform infrared analysis revealed molecular interactions between gelatin and anthocyanins, with increasing roselle extract concentrations as it showed enhanced amide A, I, II, and III functional groups. Scanning electron micrographs revealed increased surface roughness and microstructural changes with anthocyanin addition. These findings demonstrate the potential of 15% roselle anthocyanin-gelatin films as eco-friendly, pH-sensitive smart packaging materials for food applications.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared/methods
  13. Nainangu P, Mothilal SN, Subramanian K, Thanigaimalai M, Kandasamy R, Srinivasan GP, et al.
    Mol Biol Rep, 2024 Jun 12;51(1):730.
    PMID: 38864973 DOI: 10.1007/s11033-024-09666-4
    BACKGROUND: Antimicrobial resistance has surged due to widespread antimicrobial drug use, prompting interest in biosynthesizing nanoparticles from marine-derived actinomycetes extracellular metabolites, valued for their diverse bioactive compounds. This approach holds promise for addressing the urgent need for novel antimicrobial agents. The current study aimed to characterize novel bioactive compounds from unexplored biodiversity hotspots, halophilic Streptomyces sp. isolated from mangrove sediment in the Pichavaram region, India.

    METHODS AND RESULTS: Streptomyces rochei SSCM102 was conclusively identified through morphological and molecular characterization. Synthesis of silver nanoparticles (AgNPs) from Streptomyces rochei SSCM102 was characterized using various techniques, including UV-Vis, XRD, SEM, EDX, and FT-IR. The UV-Vis spectrum of the reduced AgNPs exhibited a prominent peak at 380 nm, confirming the AgNPs. The UV-Vis spectrum confirmed the synthesis of AgNP, and SEM analysis revealed a cubic morphology with sizes ranging from 11 to 21 nm. The FTIR spectrum demonstrated a shift in frequency widths between 626 cm-1 and 3432 cm-1. The EDX analysis substantiated the presence of metallic silver, evident from a strong band at 1.44 keV. The synthesized AgNPs exhibited antibacterial efficacy against human pathogens Escherichia coli (64 ± 0.32 µg/ml), Klebsiella pneumoniae (32 ± 0.16 µg/ml), and Pseudomonas aeruginosa (16 ± 0.08 µg/ml) by MIC and MBC values of 128 ± 0.64 (µg/ml), 64 ± 0.32 (µg/ml) and 32 ± 0.16 (µg/ml), respectively. Additionally, at a concentration of 400 µg/ml, the AgNPs displayed a 72% inhibition of DPPH radicals, indicating notable antioxidant capacity. The LC50 value of 130 µg/mL indicates that the green-synthesized AgNPs have lower toxicity by Brine Shrimp Larvae assay.

    CONCLUSION: The study's novel approach to synthesizing eco-friendly silver nanoparticles using Halophilic Streptomyces rochei SSCM102 contributes significantly to the field of biomedical research and drug development. By demonstrating potent antibacterial properties and aligning with sustainability goals, these nanoparticles offer promising avenues for novel antibacterial therapies.

    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared/methods
  14. Noorlaila A, Hasanah HN, Yusoff A, Sarijo SH, Asmeda R
    J Food Sci Technol, 2017 Oct;54(11):3532-3542.
    PMID: 29051648 DOI: 10.1007/s13197-017-2810-6
    The effects of xanthan gum (XG) and hydroxypropyl methylcellulose (HPMC) in sponge cakes were studied. Hydrocolloids enhanced the thickening effect in batter that affected the textural attributes of sponge cakes. During storage, the structural changes in XG-cake resulted in higher hardness compared to HPMC-cake. Similar to XG, HPMC also contributed moistness to cake. The moisture loss of cake containing XG was slower than HPMC-cake. FTIR study showed absorption of OH at region of 3600-2900 cm-1 that explained the strong interaction of water in cake containing XG compared to other cake formulations.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  15. Hosseini S, Azari P, Jiménez-Moreno MF, Rodriguez-Garcia A, Pingguan-Murphy B, Madou MJ, et al.
    Sensors (Basel), 2017 Oct 09;17(10).
    PMID: 28991214 DOI: 10.3390/s17102292
    In this article, a combination of far field electrospinning (FFES) and free-radical polymerization has been used to create a unique platform for protein immobilization via the physical attachment of biomolecules to the surface of the fiber mats. The large specific surface area of the fibers with its tailored chemistry provides a desirable platform for effective analyte-surface interaction. The detailed analysis of protein immobilization on a newly developed bio-receptive surface plays a vital role to gauge its advantages in bio-diagnostic applications. We relied on scanning electron microscopy (SEM), diameter range analysis, and X-ray photoelectron spectroscopy (XPS), along with thermal gravimetric analysis (TGA), water-in-air contact angle analysis (WCA), Fourier transform infrared spectroscopy (FTIR), and atomic force microscopy (AFM) to study our developed platforms and to provide valuable information regarding the presence of biomolecular entities on the surface. Detailed analyses of the fiber mats before and after antibody immobilization have shown obvious changes on the surface of the bioreceptive surface including: (i) an additional peak corresponding to the presence of an antibody in TGA analysis; (ii) extra FTIR peaks corresponding to the presence of antibodies on the coated fiber platforms; and (iii) a clear alteration in surface roughness recorded by AFM analysis. Confirmation analyses on protein immobilization are of great importance as they underlay substantial grounds for various biosensing applications.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  16. Gunasekaran D, Bunawan H, Ismail I, Noor NM
    Data Brief, 2018 Aug;19:1423-1427.
    PMID: 30229014 DOI: 10.1016/j.dib.2018.06.025
    In this dataset, we differentiate four different tissues of Cosmos caudatus Kunth (leaves, flowers, stem and root) obtained from UKM Bangi plot, based on Fourier transform-infrared spectroscopy. Different tissues of C. caudatus demonstrated the position and intensity of characteristic peaks at 4000-450 cm-1. Principal component analysis (PCA) shows three main groups were formed. The samples from leaves and flowers were found to be clustered together in one group, while the samples from stems and roots were clustered into two separate groups, respectively. This data provides an insight into the fingerprint identification and distribution of metabolites in the different organs of this species.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  17. Aziz SB, Hassan AQ, Mohammed SJ, Karim WO, Kadir MFZ, Tajuddin HA, et al.
    Nanomaterials (Basel), 2019 Feb 06;9(2).
    PMID: 30736346 DOI: 10.3390/nano9020216
    : In this work the influence of carbon nano-dots (CNDs) on absorption of ultra violet (UV) spectra in hybrid PVA based composites was studied. The FTIR results reveal the complex formation between PVA and CNDs. The shifting was observed in XRD spectrum of PVA:CNDs composites compared to pure PVA. The Debye-Scherrer formula was used to calculate the crystallite size of CNDs and crystalline phases of pure PVA and PVA:CNDs composites. The FESEM images emphasized the presence and dispersion of C-dots on the surface of the composite samples. From the images, a strong and clear absorption was noticed in the spectra. The strong absorption that appeared peaks at 280 nm and 430 nm can be ascribed to the n-π* and π-π* transitions, respectively. The absorption edge shifted to lower photon energy sides with increasing CNDs. The luminescence behavior of PVA:CNDs composite was confirmed using digital and photo luminescence (PL) measurements. The optical dielectric constant which is related to the density of states was studied and the optical band gap was characterized accurately using optical dielectric loss parameter. The Taucs model was used to determine the type of electronic transition in the samples.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  18. Norazelina Sah Mohd Ismail, Nazaruddin Ramli, Norziah Mohd Hani, Zainudin Meon
    Sains Malaysiana, 2012;41:41-45.
    The extraction of pectin from dragon fruit (Hylocereus polyrhizus) peels under three different extraction conditions was identified as an alternative source of commercial pectin. In this work, dried alcohol-insoluble residues (AIR) of dragon fruit peels were treated separately with 0.25% ammonium oxalate/oxalic acid at a pH of 4.6 at 85oC; 0.03 M HCl at a pH of 1.5 at 85oC; and de-ionized water at 75oC. The pectin obtained from these methods was compared in terms of yield, physicochemical properties and chemical structure. Fourier Transform Infrared Spectroscopy (FTIR) was used in the identification of dragon fruit pectins. The results showed that the pectin yield (14.96-20.14% based on dry weight), moisture content (11.13-11.33%), ash content (6.88-11.55%), equivalent weight (475.64-713.99), methoxyl content (2.98-4.34%), anhydrouronic acid (45.25-52.45%) and the degree of esterification (31.05-46.96%) varied significantly (p < 0.05) with the various extraction conditions used. Pectin extracted with ammonium oxalate gave the highest yield of pectin, with high purity and low ash content. Based on the value of methoxyl content and the degree of esterification, dragon fruit pectin can be categorized as low-methoxyl pectin.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  19. Darfizzi Derawi, Jumat Salimon
    Sains Malaysiana, 2013;42:1121-1129.
    Sebatian poliol minyak sawit olein (di-hidroksi-POo) (70% hasil) disintesis melalui pembukaan gelang oksirana minyak sawit olein terepoksida (EPOo) secara hidrolisis selanjar dan berkelompok. Hasil optimum pembukaan gelang oksirana (97.2%) bagi kedua-dua tindak balas selama 90 min (tindak balas selanjar) dan 75 min (tindak balas berkelompok) dengan menggunakan mangkin asid perklorik 3% v/wt. Spektrum transformasi Fourier inframerah (FTIR) di-hidroksi-POo menunjukkan kehadiran puncak lebar getaran regangan kumpulan hidroksil pada nombor gelombang 3429 cm-1, menunjukkan sebatian poliol telah berjaya dihasilkan. Spektrum resonan magnetik nukleus-karbon (13C-NMR) di-hidroksi-POo telah menunjukkan kehadiran puncak karbon yang terikat dengan kumpulan hidroksil (74.5 ppm). Spektrum resonan magnetik nukleus-proton (1H-NMR) di-hidroksi-POo telah menunjukkan kehadiran puncak proton yang terikat pada karbon poliol (3.4 ppm) dan proton pada kumpulan hidroksil (4.6 ppm). Kelikatan kinematik produk poliol (nilai hidroksil sebanyak 110.7 mgKOH/g minyak) adalah 1435.2 cSt (40oC) dan 55.2 cSt (100oC) dengan indeks kelikatan 78.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  20. Sasidharan S, Darah I, Jain K
    The effect of season on yield and quality of organic solvent extracts from Gracilaria changii was determined. The sustainability of the bioactive compound of G. changii from Malaysia was investigated by using the TLC and FTIR standards methods. Studies was carried out to examine the sustainability of the bioactive compound in the various extract obtained from G. changii collected from Pantai Morib, Beach Selangor Malaysia on bimonthly for a period of one year in 2003. This study revealed that the bioactive compounds was present all over the year but with different quantities. In general the variation in yield or quantities of bioactive compound was related to environment. G. changii can be considered a candidate for drug development since it retained the number of bioactive compound.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
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