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Indonesian Journal of Chemistry

ijc
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Published by Universitas Gadjah Mada

ISSN : 14119420 EISSN : 24601578 DOI : -

Core Subject : Science, Engineering,

Chemical Engineering, Chemistry & Bioengineering Chemistry

Indonesian Journal of Chemistry is an International, peer-reviewed, open access journal that publishes original research articles, review articles, as well as short communication in all areas of chemistry including applied chemistry. The journal is accredited by The Ministry of Research, Technology and Higher Education (RISTEKDIKTI) No : 21/E/KPT/2018 (in First Rank) and indexed in Scopus since 2012. Since 2018 (Volume 18), Indonesian Journal of Chemistry publish four issues (numbers) annually (February, May, August and November).

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Articles 1,981 Documents

70 71 72 73 74

Microscopic Observation of Solid-Liquid Reaction: A Novel Laboratory Approach to Teaching Rate of Reaction Agus Setiabudi; Asep Wahyudin; Galuh Yuliani; Mauro Mocerino
Indonesian Journal of Chemistry Vol 17, No 1 (2017)
Publisher : Universitas Gadjah Mada

The importance of observation in science and science education has triggered this laboratory development study that investigated the value of an observation kit as a new approach to teaching rate of reaction in general chemistry class. The kit consists of a digital microscope, a “chemical reactor”, and a tailor-made computer application and was used to video-record a solid-liquid reaction and to produce a series of two dimensional solid images that indicate the extent of reaction. The two dimensional image areas were calculated by the computer application and using the assumption that the image area was directly proportional to the mass of the solid, a plot of solid mass versus time could be obtained. These steps have been tested in several solid-liquid reaction systems, with the reaction of solid magnesium oxide with nitric acid solution resulting in the best images which were transferable to rate of reaction data, i.e. a plot of solid MgO mass as a function of time. The plot can be used to explain rate of reaction concepts including average, instantaneous, and initial rate. Furthermore, the effect of concentration on reaction rate could also be explained. This study showed that the observation kit and the generated data set have the advantage of allowing students to clearly and repeatedly visualise a solid-liquid reaction and relate this with the concept of rates of reactions. The observation kit also allows teachers and students to extend its application into inquiry based experiments.

Adsorption and Desorption of Na+ and NO3− Ions on Thermosensitive NIPAM-co-DMAAPS Gel in Aqueous Solution Eva Oktavia Ningrum; Agus Purwanto; Eka Octaviyatna Mulyadi; Dinny Islamiah Dewitasari; Sumarno Sumarno
Indonesian Journal of Chemistry Vol 17, No 3 (2017)
Publisher : Universitas Gadjah Mada

Adsorbent gel with the ability to absorb and to desorb Na+ and NO3− ions simultaneously with temperature swing was synthesized by free radical copolymerization reaction of N-isopropylacrylamide (NIPAM) and N,N-dimethyl-(acrylamidopropyl)ammonium propane sulfonate (DMAAPS). In this study, NIPAM acts as a thermosensitive agent and DMAAPS as an adsorbent agent. The purpose of this research is to investigate the effect of temperature and solution concentration on the swelling, adsorption, and desorption behaviors of NIPAM-co-DMAAPS gel. The relationship between adsorption and desorption behaviors of the gel was also elucidated. NaNO3 solution was selected as the target solution in swelling, adsorption, and desorption test. It was observed that the swelling degree of the gel increased as temperature and solution concentration raised. The adsorption amount of ions decreased with the increase of temperature. In contrast, the amount of ions desorbed from the gel increased linearly with temperature.

Radiochemical Separation of 161Tb from Gd/Tb Matrix Using Ln Resin Column Azmairit Aziz; Widya Tania Artha
Indonesian Journal of Chemistry Vol 16, No 3 (2016)
Publisher : Universitas Gadjah Mada

Terbium-161 (161Tb) is a potential radiolanthanide due to its favorable properties for treatment small size of cancer. Preliminary study on radiochemical separation of 161Tb from Gd/Tb matrix using Ln resin column based on extraction chromatography method has been carried out. 161Tb radionuclide was produced by irradiation of natural Gd2O3 target through neutron thermal bombardment at G.A. Siwabessy Multipurpose Reactor. Fractions eluted from the column containing Gd/Tb matrix of irradiated natural Gd2O3 target were identified and quantified using a γ-rays spectrometer with HP-Ge detector coupled to a multichannel analyzer. The results show that the optimum condition on 161Tb separation from irradiated Gd2O3 target with radionuclide purity 99.27 ± 0.30% was obtained using HNO3 solution with concentration of 0.8 and 3 N to separate gadolinium and terbium isotope, respectively. The yield of 161Tb obtained from the separation was 61.21 ± 2.05% and Gd recovered was 97.15 ± 2.23%. Based on this experiment, 161Tb has been separated from irradiated natural gadolinium oxide target with high radionuclide purity.

Chalcone Based Colorimetric Sensor for Anions: Experimental and TD-DFT Study Adita Silvia Fitriana; Harno Dwi Pranowo; Bambang Purwono
Indonesian Journal of Chemistry Vol 16, No 1 (2016)
Publisher : Universitas Gadjah Mada

The interactions between sensor chalcone of 3-(4-hydroxy-3-methoxyphenyl)-1-phenyl-2-propen-1-one (1) and anions (F–, Cl–, Br–, CN–, CO32–, and SO42–) have been experimentally and TD-DFT theoretically investigated. Sensor (1) showed a naked-eye detectable color change from yellow to red upon addition of F–, CO32–, CN–, and SO42– anions in DMSO, whereas no significant color change was observed upon addition of Cl– and Br– anions. The interaction models were predicted by optimizing (1)-anion complex using DFT/B3LYP method. Optimized (1)-anion complexes showed that sensor (1) was deprotonated by CO32–, CN–, F–, and SO42–. The formation of deprotonated sensor (1)– was responsible for the colorimetric signaling. Absorption spectra of neutral and deprotonated sensor were calculated using TD-DFT method. The calculated spectra were in good agreement with experimental results.

Preponderance of Bioactive Medicinal Compounds and ATR-FTIR Spectroscopy of Coriander and Mustard Floral Honey from Apis mellifera Ishan Ullah Khan; Widhi Dubey; Vedprakash Gupta
Indonesian Journal of Chemistry Vol 17, No 3 (2017)
Publisher : Universitas Gadjah Mada

The physicochemical, total phenolics, flavonoids, and antioxidant activity were evaluated for biochemical characterization of coriander and mustard floral honey. The total phenolics, flavonoids and antioxidant activity were analyzed using UV-VIS spectrophotometer. Fourier transform infrared spectroscopy (FT-IR) was used to evaluate the chemical characteristic of coriander and mustard floral honey. The total phenolics content was ranged from 294 to 462 mg gallic acid equivalent kg-1 of honey. The total flavonoid content was ranged from 43 to 53 mg quercetin equivalent kg-1 of honey. Antioxidant activity results were expressed as inhibitory concentration (IC50) value ranged from 4.58 to 5.54 mg mL-1. FT-IR spectra showed the presence of alcohols, carboxylic acids, esters, ethers, phenols, and amines in both floral honey samples. This study discovered that coriander floral honey is more affluent than mustard floral honey in nutritional as well as medicinal aspects. At a glance the processing of honey by heating did not affect the phenolics, flavonoid, and antioxidants of honey; even processed honey contains higher phenols and antioxidants. The FT-IR spectra showed the similarity in both kinds of honey refers to chemical constituents. This study will help the researcher and honey consumer to find out the higher bioactive medicinal compounds containing honey.

Hydrocracking of α-Cellulose Using Co, Ni, and Pd Supported on Mordenite Catalysts Wega Trisunaryanti; Triyono Triyono; Ria Armunanto; Lathifah Puji Hastuti; Desinta Dwi Ristiana; Resi Vita Ginting
Indonesian Journal of Chemistry Vol 18, No 1 (2018)
Publisher : Universitas Gadjah Mada

Hydrocracking of α-cellulose has been conducted in a semi-batch reactor at 400, 450, and 500 °C with hydrogen flow (30 mL/min.) for 4 h. Mordenite (MOR) and Co, Ni and Pd metal supported on the MOR were used as solid catalysts. The catalysts were characterized using X-ray Diffractometer (XRD), Fourier Transform Infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM) to evaluate the physical-chemical properties. Energy Dispersive X-ray (EDX) and Inductively Coupled Plasma (ICP) were used to analyze the amount of metal impregnated on the catalysts. The liquid product was analyzed using Gas Chromatograph-Mass Spectroscopy (GC-MS). Thermal hydrocracking was also conducted at 450 °C with the amount of liquid product was 37.86 wt.%. The highest liquid conversion obtained by mordenite catalyst was 94.66 wt.% at 450 °C and the highest liquid conversion (98.08 wt.%) was reached by Pd/MOR catalyst at 400 °C.

Preparation of CaTiO3 Asymmetric Membranes Using Polyetherimide as Binder Polymer Endang Purwanti Setyaningsih; Maya Machfudzoh; Wahyu Prasetyo Utomo; Hamzah Fansuri
Indonesian Journal of Chemistry Vol 16, No 1 (2016)
Publisher : Universitas Gadjah Mada

Asymmetric dense and thin membranes have been prepared from powders of perovskite oxide-type CaTiO3 without cracking by phase inversion method. Polyetherimide was used as a polymeric binder in the method. The resulting green membranes, composed of CaTiO3 powder and polyetherimide binder, were sintered at 890, 1100 or 1200 °C. The crystal phase of CaTiO3 was analyzed using X-Ray Diffraction (XRD). The XRD pattern of the synthesized CaTiO3 powder was matched with the reference indicating the formation of CaTiO3 structure. Sintering at 890 °C fails to form a strong membrane. Scanning Electron Microscope (SEM) images of the membranes showed that the membrane had the asymmetric structure with dense layer on one side and porous layer on the other side. The pores in the porous layer were both finger-like and sponge-like structure. The mechanical strength of the membranes, which were determined by Vickers micro hardness method, varied from 3.5 to 25.8 Hv. The strongest membrane without any crack was resulted from sintering at 1200°C with hardness values between 19.4 and 25.8 Hv. Thermal expansion coefficients of the asymmetric membranes sintered at 1100 and 1200 °C, measured with Thermomechanical Analyzer (TMA), were 10.82 × 10-6 and 12.78 × 10-6.C-1 respectively.

Adsorption of β-Carotene in Isopropyl Alcohol with Decolorized Activated Carbon as Model for β-Carotene Adsorption in Crude Palm Oil Maria Ulfah; Sri Raharjo; Pudji Hastuti; Purnama Darmadji
Indonesian Journal of Chemistry Vol 17, No 1 (2017)
Publisher : Universitas Gadjah Mada

The objective of this research was to characterize the porosity of decolorized activated carbon (DAC) and its ability to adsorb β-carotene as a preliminary study to characterize activated carbon as an adsorbent to adsorb carotene from crude palm oil. The capability of DAC to adsorb β-carotene was studied using isopropyl alcohol as a solvent in equilibrium conditions. The adsorption time was specified for 0.5 to 60 min, while the DAC optimum concentration for adsorption of β-carotene was determined at a concentration of 0.5 to 2.5%. Adsorption isotherm study was conducted for a β-carotene concentration of 100 to 500 ppm and at temperatures of 30, 40 and 50 °C at equilibrium time and DAC optimum concentration. The results showed that the DAC had a surface area of 1068.391 m2/g, total pore volume of 0.952 cc/g, mesopore volume of 0.528 cc/g (55.4%) and mesopore radius of 15.26 Å. Based on the levels of β-carotene adsorbed onto the DAC, the equilibrium was reached after adsorption of 5 min. Decolorized activated carbon with a concentration of 1.5% was able to adsorb β-carotene optimally. Adsorption of β-carotene at 40 °C for 60 min according to Freundlich models with the intensity of adsorption of 1.002 and adsorption capacity of 63.358 L/mg. While the adsorption of β-carotene at 50 °C for 60 min in accordance with the model of Langmuir, the adsorption capacity of 33.206 mg/g and the Langmuir adsorption equilibrium constant of 1.721 L/mg.

An Ellagic Acid Derivative and Its Antioxidant Activity of Stem Bark Extracts of Syzygium polycephalum Miq. (Myrtaceae) Tukiran Tukiran; Andika Pramudya Wardana; Nurul Hidayati; Kuniyoshi Shimizu
Indonesian Journal of Chemistry Vol 18, No 1 (2018)
Publisher : Universitas Gadjah Mada

The investigation of the Syzygium polycephalum Miq. (Myrtaceae) aimed to assess the phytochemical contents and antioxidant activity of the chloroform fraction. In this study, the fraction was obtained from methanol extract of S. polycephalum stem bark partitionated by chloroform. An ellagic acid derivative was successively isolated from the chloroform fraction. The molecular structure of isolated compound was elucidated and established as 3,4,3’-tri-O-methylellagic acid through extensive spectroscopic studies including UV-Vis, FTIR, NMR and LC-MS analyses and by comparison with literature data. The finding of the isolated compound is the first time from the plant, although the isolated compound previously have been found in the other Syzygium species such as S. cumini together with ellagic acid and 3,3’-di-O-methylellagic acid. The chloroform fraction, isolated compound, and vitamin C showed antioxidant activity against 2,2’-diphenyl-1-picrylhydrazyl (DPPH) with IC50 value of 163.6, 72.1, and 11.5 μg/mL, respectively.

Photocatalytic and Photoelectrocatalytic Degradation of Methyl Orange Using Graphite/PbTiO3 Composite Candra Purnawan; Sayekti Wahyuningsih; Pramudita Putri Kusuma
Indonesian Journal of Chemistry Vol 16, No 3 (2016)
Publisher : Universitas Gadjah Mada

Synthesis of graphite/PbTiO3 composite as a catalyst in photodegradation and photoelectrodegradation process of methyl orange have been conducted. The purposes of this research are to study the effect of radiation time, composition of composite, voltage and pH of solution for methyl orange degradation. Photodegradation process of methyl orange was carried out for 5; 10; 15; 20; 25 and 30 min. Ratio of graphite : PbTiO3 (w/w) were varied at 1:3; 1:2; 1:1; 2:1 and 3:1. Meanwhile, the applied voltages were 7.5; 10 and 12.5 V and the photoelectrodegradation was conducted under pH condition of 3; 7; and 11, respectively. The result showed that optimum composition of graphite/PbTiO3 in the methyl orange photodegradation was obtained at 1:1 ratio for 30 min with degradation up to 90.43% ± 0.062. The degradation reaction follows first order reaction with a rate constant of 0.0688 min-1. The optimum voltage is 10 V, in which it reduced the methyl orange concentration up to 92.65% ± 0 with a rate constant 0.0941 min-1 for first order reaction. The optimum pH is pH = 11, that provide methyl orange reduction up to 95.28% ± 0.082.

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