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Indonesian Journal of Chemistry

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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

59 60 61 62 63

STUDY OF CATALYTIC CYCLISATION OF (+)-CITRONELLAL WITH Zn/γ-ALUMINA AS CATALYST Elvina Dhiaul Iftitah; Hardjono Sastrohamidjojo; M. Muchalal
Indonesian Journal of Chemistry Vol 4, No 3 (2004)
Publisher : Universitas Gadjah Mada

The reaction of catalytic cyclisation of (+)-citronellal has been done using g-alumina and Zn/γ-alumina as catalysts. Zn/γ-alumina catalyst was prepared by impregnation of ZnBr2 into solid of γ-alumina in methanol as a solvent. The calcination process is performed on Muchalal reactor at 400 oC. The reactions were carried out under nitrogen gas atmosphere by mixing 5 mL sample and 1.0 g catalyst at 90-95 oC for 3 hours. The product of reaction was analyzed using GC, FT-IR and GC-MS. The reaction of cyclization of (+)-citronellal with γ-alumina catalyst did not give targeted product as well as reaction with Zn/g-alumina catalyst. Whereas, the reactions with Zn/γ-alumina catalyst gave four compounds of isopulegol stereoisomer. Conversion of (-)-Isopulegol, (+)-Neoisopulegol, (+)-Isoisopulegol and (+)-Neoisoisopulegol were 64,29%, 18,80%, 9,20% and 3,32% respectively. For that reason, the transformation of (+)-sitronelal using Zn/γ-alumina was considered to be the best catalyst. A reaction mechanism is proposed where the (+)-citronellal molecule binds to a catalyst Lewis acid site via the aldehyde oxygen and the π-electrons of the double bond. Subsequent protonation of the aldehyde via a neighbouring Bronsted acid site initiates the cyclisation to isopulegol.

EFFECT OF ZEOLITE 4A ON WATER CONCENTRATION IN THE SYSTEM OF THE ESTERIFICATION REACTION OF ACETIC ACID WITH 1-BUTANOL Ratna Dewi Kusumaningtyas
Indonesian Journal of Chemistry Vol 6, No 2 (2006)
Publisher : Universitas Gadjah Mada

The usual problem encountered on a reversible reaction is that the reaction cannot achieve a complete conversion of reactants since it is limited by the thermodynamic equilibrium. Due to this low conversion, it will face challenges with product purification and recycling of the reactants, which then cause an increase in the operation cost. To obtain higher conversion, it is necessary to shift the equilibrium towards the products by continuously removing the water formed. One popular example of reversible reaction is esterification process. In this research, water removal was conducted through an adsorption process using zeolite 4A. Effect of zeolite 4A on water concentration in the liquid phase esterification of acetic acid and 1-butanol catalyzed by sulfuric acid was investigated. It was performed in an isothermal batch reactor. The molar ratio of 1-butanol - acetic acid was 1.4 times theoretically, the catalyst concentration was 1 % wt and the mixing intensity was 1000 rpm. The influence of the temperature was studied at 40 to 80 °C and the zeolite 4A loading was varied at 1.6 to 5.52 % w/ v. The reaction was compared to the conventional esterification reaction carried out under identical conditions but without addition of zeolite 4A. Concentration of each component in the system was analyzed using on-line Gas Chromatography. Effect of removing the water produced during the reaction by using zeolite 4A was demonstrated. It was revealed that the amount of water removed was proportional to the amount of the zeolite 4A to be employed. On the other hand, the increase of the temperature led to the lower amount of water to be adsorbed. Among all the experiments, the best result was achieved on the addition of 5.52 % b/v zeolite 4A at 40 °C, where water concentration was 3.1356 g mole/L and the conversion was 76.11 % at the equilibrium condition. As comparison, water concentration on the conventional reaction performed at 40 °C was 6.9161 g mole/L and the conversion was 62.5 % at the equilibrium condition. The equation illustrating the effect of zeolite 4A loading on the conversion obtained at the equilibrium condition was: XAe = 0.6248 + 0.0868 C4A0.2848, where XAe was equilibrium conversion of Acetic Acid and C4A was Zeolite 4A loading (g/100 mL liquid).

SELF-CLEANING GLASS BASED ON ACID-TREATED TiO2 FILMS WITH PALMITIC ACID AS MODEL POLLUTANT Nurul Hidayat Aprilita; Indriana Kartini; Sofy Herawati Ratnaningtyas
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

Preparation and characterization of self-cleaning glass based on acid-treated TiO2 films as well as evaluation on their self-cleaning properties have been carried out. Palmitic acid photodegradation was used as model pollutant. Acid-treated TiO2 powders were deposited on glass surface by using spraying technique. The XRD results showed that acid-treated TiO2 film exhibited decreased anatase crystalline size. The corresponding SEM images showed porous surface morphology. Layer densification was observed as the film thickness increased. TiO2 photocatalytic activity increased as the length of UV radiation increased. Best results were obtained at experimental condition of 35 hours UV radiation time. It is also observed that the thickness of TiO2 layers influenced the efficiency of palmitic acid photodegradation. The film with 1.661 µm thick TiO2 layers and 6.933 mg weight (0.7164 mg/cm2) could degrade 97.54 % mg palmitic acid/cm2 thin film.

STUDY ON THE SYNTHESIS OF MONOLAURIN AS ANTIBACTERIAL AGENT AGAINTS Staphylococcus aureus Galuh Widiyarti; Muhammad Hanafi; Wahyudi Priyono Soewarso
Indonesian Journal of Chemistry Vol 9, No 1 (2009)
Publisher : Universitas Gadjah Mada

The monolaurin compound had been synthesized from lauric acid and glycerol by using sulfuric acid (H2SO4) as catalyst. The synthesis of monolaurin was done by batch esterification on the free solvent system. The esterification reaction was performed on the equivalent mol ratio between lauric acid and glycerol 1:1, in the presence of 5% H2SO4, at 130 °C, for 6 hours, produced ester compounds on 59.29%. The products of column chromatography on silica gel purification are monolaurin and dilaurin in amount of 31.05 and 4.48%, respectively. The monolaurin and dilaurin were identified by TLC, FTIR, GC-MS, and NMR spectrometer. The spectral data of monolaurin was compared to spectral data of standard monolaurin. The result of NMR identifications showed that synthesis products were a-monolaurin and a,a'-dilaurin. The antibacterial activity of synthesis products was tested against Staphylococcus aureus. The activity result showed that the antibacterial activity of monolaurin is more active than dilaurin.

STUDY OF ELECTROPOLIMERIZATION PROCESSES OF PYRROLE BY CYCLIC VOLTAMMETRIC TECHNIQUE Adhitasari Suratman; Buchari Buchari; Indra Noviandri; Suryo Gandasasmita
Indonesian Journal of Chemistry Vol 4, No 2 (2004)
Publisher : Universitas Gadjah Mada

Electropolymerization processes and electrochemical properties of polypyrrole as electroactive polymer have been studied by cyclic voltammetric technique. Pyrrole was electropolymerized to form polypyrrole in water-based solvent containing sodium perchlorate as supporting electrolyte in several pH values. The pH of the solutions were varied by using Britton Robinson buffer. The results showed that oxidation potential limit of electropolymerization processes of pyrrole was 1220 mV vs Ag/AgCl reference electrode. It can be seen that cyclic voltammetric respon of polypyrrole membrane that was prepared by electropolymerization processes of pyrrole at the scanning rate of 100 mV/s was stable. While the processes of pyrrole electropolymerization carried out at the variation of pH showed that the best condition was at the pH range of 2 - 6.

SORPTION-DESORPTION MECHANISM OF Zn(II) AND Cd(II) ON CHITIN Sri Juari Santosa; Narsito Narsito; Aldes Lesbani
Indonesian Journal of Chemistry Vol 6, No 1 (2006)
Publisher : Universitas Gadjah Mada

This study reports the results of the elucidation of the sorption-desorption mechanism of Zn(II) and Cd(II) on chitin through the determination of capacity, energy, and rate constant of sorption as well as the investigation of their desorption properties in NaCl and Na2EDTA solutions. The chitin was isolated through deproteination followed by demineralization of crab (Portunus pelagicus Linn) shell using NaOH solutions. The sorption of both metal ions followed the Langmuir isotherm model, resulting the sorption capacities of 3.2 x 10-4 and 2.8 x 10-4 mol g-1 for Zn(II) and Cd(II), respectively, and sorption energies of 15.1 kJ mol-1 for Zn(II) and 17.9 kJ mol-1 for Cd(II). It was also observed that Zn(II) was sorbed slightly faster than Cd(II) with first order sorption rate constants of 2.82 x 10-3 min-1 for Zn(II) and 2.61 x 10-3 min-1 for Cd(II). The result of the desorption experiment showed that Cd(II) and especially Zn(II) could only be exchanged by Na(I) after desorbing those metal ions by strong chelating agent of EDTA2-. The easier desorption of Zn(II) than Cd(II) by EDTA2- must be attributed by the smaller sorption energy of Zn(II) and by harder acid property of Zn(II) than Cd(II) as EDTA2- contained hard electron donor elements.

ENRICHMENT OF α-( ALPHA) LINOLENIC ACID OF BASIL SEED OIL, Ocinum Basillium L. BY FRACTIONAL CRYSTALIZATION AND CRYSTALIZATION IN UREA INCLUSION COMPLEXES Warsito Warsito; Jumina Jumina; Chairil Anwar; Rurini Retnowati; Ahmad Ghanaim; Suleman Duengo
Indonesian Journal of Chemistry Vol 11, No 1 (2011)
Publisher : Universitas Gadjah Mada

Enrichment of α-(alpha) linolenic acid (ALA) of basil seed oil, Ocinum basilicum L. can be done by fractional crystalization and crystalization of fatty acid in urea inclusion complexes (UIC) methods. In this research, the ALA of fatty acid of basil seed oil was fractionated by fractional crystallization in methanol solution at -3, -13 and -25 °C and by crystallization in urea solution (ratio 1:2) at 4, 2, -6 and -8 °C. The ALA percentages were analyzed by GC and GC/MS. The results showed that percentage of ALA obtained from fractional crystallization at -25 °C increase from 65.16 to 91.40, and acquired from UIC is 98.8 at 2 °C

PHYTOCHEMICAL STUDIES OF THE PETROLEUM ETHER EXTRACT OF THE LEAVES OF Lagerstroemia speciosa Linn S.M. Mizanur Rahman; Shayla Pervin; Md. Abdul Quader; M. Amzad Hossain
Indonesian Journal of Chemistry Vol 9, No 3 (2009)
Publisher : Universitas Gadjah Mada

Two new compounds, normal alcohol containing of higher carbons and isomer of β-sitosterol were isolated for the first time from the petroleum extract of the leaves of Lagerstroemia speciosa. The structure of the compound has been established on the basis of UV, IR, 1H-NMR, 13C-NMR and mass spectra and identified as nonanol and isomer of β-sitosterol.

THE SYNTHESIS OF Cr2O3-PILLARED MONTMORILLONITE (CrPM) AND ITS USAGE FOR HOST MATERIAL OF p-NITROANILINE Karna Wijaya; Iqmal Tahir; Ahmad Baikuni
Indonesian Journal of Chemistry Vol 2, No 1 (2002)
Publisher : Universitas Gadjah Mada

The synthesis of Cr2O3-pillared montmorillonite (CrPM) and its usage for host material of p-nitroaniline have been conducted. The Cr2O3-pillared montmorillonite clays was prepared by a direct ion exchange method. First, the polyhydroxychromium as a pillaring spesies was intercalated into the interlayer region of the montmorillonite clays (purified clay in the monocation form), result in a montmorillonite-polyoxychromium intercalation compound. The precursors/pillaring spesies was not stable, hence it must be stabilized by calcination in order to transform the polyoxychromium via dehydration and dehydroxylation processes into Cr2O3. This oxide constituts the so-called pillar that prop the clay layers apart to a relatively large distance. The Cr2O3-pillared clays as a host material was added into ethanol solution saturated with p-nitroaniline, and mixture was stirred for 24 h at room temperature. The Na-montmorillonite, Cr2O3-pillared clay and p-nitroaniline-Cr2O3-pillared clay (pNA-CrPM) were characterized by X-Ray Diffraction (XRD), Gas Sorption Analysis, Infrared Spectroscopy (FTIR) and Activated Neutron Analysis (ANA) methods. The result of research showed that basal spacing (d001) of Cr2O3-pillared montmorillonite (CrPM) was 18,55 Å, meanwhile the basal spacing of the hydrated Na-montmorillonite was 14,43 Å. The specific surface area of the Cr2O3-pillared montmorillonite was 174,308 m2/g, whereas p-nitroaniline-Cr2O3-pillared clay (pNA-CrPM) was 133,331641 m2/g. This fact indicated that p-nitroaniline has been included into the pore of the Cr2O3-pillared clay.

DETERMINATION OF NITRITE AS 4-(4-NITROBENZENAZO)-1-AMINONAPHTHALENE DYE USING OPTICAL MEMBRANES BASED ON PVC-DOS MATRIX Choirul Amri; Dwi Siswanta; Mudasir Mudasir
Indonesian Journal of Chemistry Vol 5, No 3 (2005)
Publisher : Universitas Gadjah Mada

A study of a liquid polymeric membrane based on polyvinylchloride-dioctylsebacate (PVC-DOS) as optical membrane for the spectrophotometric and visual determination of nitrite has been done. The method relied on the formation of a purple colored 4-(4-nitrobenzenazo)-1-aminonaftalen dye in the membrane. The result showed that liquid polymeric membrane can be used as an optical membrane for the determination of nitrite. Optimum conditions of method achieved at a wavelength of 525 nm, reaction pH of 1.7-1.8, and respon time of 45 minutes. This method gave linear range of concentration at 0.0-0.17 mg/L NO2--N, detection limit of 0.004 mg/L NO2--N, and sensitivity of 4.981+0.110 absorbance unit per mg/L of NO2--N. The spectrophotometric and visual optical membrane method by is good for the determination of nitrite at the concentration range of 0.01-0.11 mg/L NO2--N and 0.02-0.60 mg/L NO2--N, respectively.

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