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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).

Arjuna Subject : -

Articles 1,981 Documents

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MODELING OF ALKYL SALICYLATE COMPOUNDS AS UV ABSORBER BASED ON ELECTRONIC TRANSITION BY USING SEMIEMPIRICAL QUANTUM MECHANICS ZINDO/s CALCULATION Iqmal Tahir; Karna Wijaya; Titik Subarni
Indonesian Journal of Chemistry Vol 2, No 1 (2002)
Publisher : Universitas Gadjah Mada

Modeling of several alkyl salicylates based on electronic transition by using semiempriical mechanical quantum ZINDO/s calculation has been done. Object of these research were assumed only alkyl salicylates of C4 (butyl) until C8 (octyl) homologue with 4-7 example structures of each homologue. All of the computation have been performed using quantum chemistry - package software Hyperchem 6.0. The research covered about drawing each of the structure, geometry optimization using semiempirical AM1 algorithm and followed with single point calculation using semiempirical ZINDO/s technique. ZINDO/s calculations used a defined criteria that is singly excited - Configuration Interaction (CI), gap of HOMO-LUMO energy transition was 2 and degeneracy level was 3. Analysis of the theoretical spectra was focused in the UV-B (290-320 nm) and UV-C (200-290 nm) area. The result showed that modeling of the compound can be used for predicting the type of UV protection activity depending with the electronic transition in the UV area. Modification of the alkyl homologue relatively did not change the value of wavelength absorbtion to indicate the UV protection activity. Alkyl salicylate compounds were predicted as UV-C sunscreen or relatively the compounds have protection effect for UV-C.

STUDY ON SENSITIZATION OF FULVIC ACID ON PHOTOREDUCTION OF Cr(VI) TO Cr(III) BY TiO2 PHOTOCATALYST Uripto Trisno Santoso; Kamilia Mustikasaria; Sri Juari Santosa; Dwi Siswanta
Indonesian Journal of Chemistry Vol 7, No 1 (2007)
Publisher : Universitas Gadjah Mada

Sensitization of fulvic acid (FA) on photoreduction of Cr(VI) to Cr(III) by TiO2 photocatalyst has been studied. Parameters influencing the sensitization, i.e., pH of medium, as well as FA concentrations, TiO2 concentrations and initial Cr(VI) concentrations were critically evaluated. Extraction of FA from peat soil sampled in Gambut, South Kalimantan, Indonesia, was performed using Amberlite XAD-7 resin. The FA extract then was purified by cation exchange method using Amberlite IRA-120 resin. The TiO2 produced by Merck was used as semiconducting photocatalyst and two 30-W UV lamps (Philips® model TUV) were used as photon source. The results showed that presence of FA on TiO2 suspensions could sensitize the photoreduction of Cr(VI), enhancing of the amount of reduced Cr(VI) more significantly than the sensitization by humic acid. The effectiveness of this sensitization increased with increasing initial concentrations of FA, TiO2, or Cr(VI) until certain concentration, but no further improvement can be observed in excess FA, TiO2, or Cr(VI) concentrations. On the contrary, the effectiveness of this sensitization decreased with increasing of the medium pH.

EFFECT OF ACID CONCENTRATION ON CHARACTERS OF SILICA GEL SYNTHESIZED FROM SODIUM SILICATE Nuryono Nuryono; Narsito Narsito
Indonesian Journal of Chemistry Vol 5, No 1 (2005)
Publisher : Universitas Gadjah Mada

In this research, synthesis and characterization of silica gel from sodium silicate through sol-gel process using H2SO4, HCl, and citric acid have been investigated. Synthesis was carried out by mixing and stirring 20 mL of H2SO4, HCl or citric acid at certain concentration with 50 mL of sodium silicate solution (Na2O 0.17 M and SiO2 0.61 M) for one hour and let to form gel. The gel was washed with distillated water, and dried in an oven at 100 oC. Characterization of silica gel was carried out by determination of acidity, water adsorption capacity, and water content. Identification of functional group and structure were identified using x-ray diffractometer (XRD) and infrared (IR) spectrophotometer, respectively. Results showed that at a range of investigated concentration (0.6 - 3.0 M) the increase of concentration, formation of gel with H2SO4 tended to be faster, but with HCl and citric acid to be slower. The increase of acid concentration caused water content, water adsorption capacity, and acidity of the silica gel resulted with HCl and citric acid tended to be increased, increased, and increased, but with H2SO4 to be decreased, increased, and decreased, respectively. Based on the IR spectra and XRD data, it could concluded that the synthetic silica gels contained silanol (Si-OH) and siloxane (Si-O-Si) and were amorphous, showing similar pattern to kieselgel G 60 produced by Merck.

STUDY OF NaOH - ACTIVATION TEMPERATURE INFLUENCE TOWARD CHARACTER OF MESOPOROUS CARBON BASED ON TEXTILE SLUDGE WASTE Tutik Setianingsih; Uswatun Hasanah; Darjito Darjito
Indonesian Journal of Chemistry Vol 8, No 3 (2008)
Publisher : Universitas Gadjah Mada

Textile sludge waste contains many organic matters so that it is potential to be used as mesoporous carbon precursor. Actived carbon with mesopore character is effective as adsorbent and catalyst carrier of large molecules. Synthesis of the activated mesoporous carbon was done with purpose to study influence of activation temperature toward characters of the carbon. Process of the synthesis involved dry sludge (50 g) as precursor, concentrated sodium silicate solution SiO2 24.5% and Na2O 7.5% (50 mL) as template source, 1 M HCl solution (50 mL) as polimering agent, carbonization condition at 600 °C 3 h under nitrogen gas flow, activation conditions with NaOH 50% and various temperatures (400, 500, 600, 700, and 800 °C), and demineralizatin conditions with 0.1 M HCl solution for 4 h and 125 rpm. All of the products were characterized with methylen blue method to determine specific pore volume and specific surface area. The carbon obtained at optimum temperature was characterized again with surface area analyzer. Result of the research showed that the optimum condition was achieved at activation temperature of 500 °C. Characters of the synthesized carbon at the optimum condition were specific surface area of 638.32 m2/g, specific pore volume of 0.35 cm3/g, average pore diameter of 21.78 Å, and methylene blue number of 358.87 mg/g.

ISOLATION ANTHOCYANIN FROM ROSELLE PETALS (Hibiscus sabdariffa L) AND THE EFFECT OF LIGHT ON THE STABILITY Siti Nuryanti; Sabirin Matsjeh; Chairil Anwar; Tri Joko Raharjo
Indonesian Journal of Chemistry Vol 12, No 2 (2012)
Publisher : Universitas Gadjah Mada

This study was conducted to isolate anthocyanins from roselle petals and testing the stability toward light. Isolation of anthocyanin was accomplished by extracting roselle petals using eluents with different polarity levels. Nonpolar compounds was eliminated using n-hexane, then semipolar compounds extracted with ethyl acetate and isolated anthocyanin by solvent mixtures of methanol-HCl 0.5%. Color test to determine the presence of anthocyanin was performed with NH3 vapor, Pb-acetate 1% and Pb-nitrate 5%. The structure of anthocyanin in the roselle flower was determined using UV-Vis spectrophotometer, FT-IR and 1H-NMR. Anthocyanin stability test of the influence of light carried out in a room without light conditions (dark room) and light 25 Watt at 31 °C. The results showed that the roselle petals contain anthocyanin cyanidin-3-glucoside. Light has been found to affect the stability of anthocyanin cyanidin-3-glucoside.

PREPARATION, CHARACTERIZATION, AND CATALYTIC ACTIVITY TEST OF Ni-Mo/NATURAL ZEOLITE ON PYRIDINE HYDRODENITROGENATION Sri Kadarwati; Sri Wahyuni; Wega Trisunaryanti; Triyono Triyono
Indonesian Journal of Chemistry Vol 10, No 3 (2010)
Publisher : Universitas Gadjah Mada

Preparation, characterization, and catalytic activity test of Ni-Mo/natural zeolite on pyridine hydrodenitrogenation were carried out. Preparation of catalyst was conducted by impregnation method using nickel nitrate hexahydrate and ammonium heptamolibdate precursor as Ni and Mo source respectively. Characterization of catalyst was conducted by using gravimetry, atomic absorption spectrophotometry, and X-ray diffraction method. Catalytic activity test on pyridine hydrodenitrogenation was carried out by using flow system reactor with hydrogen flow rate variable. The research results showed that the catalyst's total acidity and crystallinity are increased with level of impregnation success of 96.71% and 90.08% respectively. Ni-Mo/natural zeolites able to increase the catalytic conversion up to 71.78% at 350 °C and hydrogen flow rate of 10 mL/min with more highly varied product distribution. Assuming that the pyridine hydrodenitrogenation follows the pseudo first order kinetics.

SYNTHESIS OF SECONDARY ALCOHOL COMPOUNDS FROM SAFROLE AND METHYLEUGENOL Hanoch J Sohilait; Hardjono Sastrohamidjojo; Sabirin Matsjeh
Indonesian Journal of Chemistry Vol 3, No 3 (2003)
Publisher : Universitas Gadjah Mada

Synthesis of secondary alcohols compound from safrole and methyleugenol has been achieved through conversion of allyl group to alcohol.The reaction of safrole and methyleugenol with mercuric acetate in aqueous tetrahydrofuran, followed by in situ reduction of the mercurial intermediate by alkaline sodium borohydride produced secondary alcohol namely safryl alcohol (71.25%) and methyleugenil alcohol (65.56%). The structure elucidation of these products were analyzed by FTIR, 1H-NMR, 13C-NMR and MS.

ALDOL CONDENSATION OF N-ALKYLATED-3-ARYL-4,6-DIMETHOXY-7-FORMYLINDOLES AS A GOOD METHOD FOR THE SYNTHESIS OF 1-ARYL-6,8-DIMETHOXYPYRROLO[3,2,1-hi]INDOLE-4-CARBOXYLATES Jumina Jumina
Indonesian Journal of Chemistry Vol 6, No 3 (2006)
Publisher : Universitas Gadjah Mada

Alkylation of 3-aryl-4,6-dimethoxyindole 3a and 3b with methyl and ethyl a-bromoacetates afforded good yields of indol-1-ylacetates 4. Treatment of these indoles 4 with the Vilsmeier formylation reagent gave formylindoles 5 in 54-81 % yield. These formylindole 5 underwent intramolecular aldol condensation when treated with sodium hydride in tetrahydrofuran to give pyrroloindole-4-carboxylates 6 in 30-60 % yield. Structural assignment based on spectroscopic data confirmed the structure of the synthesized pyrroloindoles. In the case of pyrroloindole 6c, the structure of this molecule was also proven by X-ray crystallography data.

THE USE OF TIO2-ZEOLIT AS A CATALYST ON THE DEGRADATION PROCESS OF ERIONIL RED DYE Agustin Sumartono; Winarti Andayani
Indonesian Journal of Chemistry Vol 7, No 2 (2007)
Publisher : Universitas Gadjah Mada

Degradation of erionil red dye using photo catalytic processes with TiO2-zeolit as a catalyst was carried out. Degradation of the dye was observed in 10 L volume, and erionil red dye was used as a model of organic pollutant. The parameters examinated were intensity of the spectrum, the decrease of pH, percentage of degradation, and the efectifity TiO2-zeolit as a catalyst. The use of UV lamp and TiO2-zeolit as a catalyst showed a good results because the dye could be degraded. This could be seen from the decreasing of the intensity of the spectrum 24 h after illumination. The pH of erionil red increased from around 4 into 5.5 which is still acidic. Effectivity of TiO2 composit as a catalyst could be used only two times. The compound resulted from degradation that could be detected using HPLC was oxalic acid.

ADSORPTION OF AN NH3 MOLECULE ON Cr(111) SURFACE BY QCMP 116 PROGRAM Charles Banon
Indonesian Journal of Chemistry Vol 10, No 1 (2010)
Publisher : Universitas Gadjah Mada

Interactions of an NH3 molecule on chromium (111) surface consists of 20 atoms with three layers has been studied by QCMP 116 (Calzaferri) program, run on IBM PC compatible (Pentium III, 660 MHz). An oncoming NH3 (with the planar molecular plane parallel or perpendicular to surface), at many positions, was optimized three dimensionally by that program. Observing the binding energy of an NH3 on surface (BE (NH3)) and inter atomic distances at the optimized conditions. It's showed that: an oncoming NH3 molecule, with molecular plane parallel to the surface, N atom was oriented to atoms of the first and third layer. One of its NH bond was parallel to the Cr-Cr bond were chemisorbed molecularly with BE(NH3) in range of 0.9797-1.3421 eV/molecule. On the second layer was chemisorbed atomically. However, an oncoming NH3 with molecular plane perpendicular to the surface (with N atom and one of its N-H bond perpendicular to Cr atom) was adsorbed physically with BE(NH3) in a range of 0.4903-0.5614 eV/molecule.

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